var TEXT = 1;
var NUMBER = 2;
var EMAIL = 3;
var DATE = 4;
var DATETIME = 5;
var TIME = 6;

function validate_field(field_obj, field_name, field_type)  {
    //field_obj must be a valid form field
    if (field_obj.value.search(/\S/)==-1)   {
        alert("Please fill in " + field_name);
        field_obj.focus();
        return 0;
    }
    else    {
        //checking for email if needed
        if (field_type == EMAIL)    {
            if (field_obj.value.search(/^[^@ ]+@[^@ ]+\.[^@ \.]+$/) == -1)   {
                alert("Please fill in valid " + field_name);
                field_obj.focus();
                return 0;
            }
            return 1;
        }
        else if (field_type == NUMBER)  {
            if (isNaN(field_obj.value)) {
                alert("Please fill in valid " + field_name);
                field_obj.focus();
                return 0;
            }
            else
                return 1;
        }

        else if (field_type == DATE)    {
            if (field_obj.value.length == 10 &&
                field_obj.value.search(/(0[1-9]|[12][0-9]|3[01])\/(0[1-9]|1[012])\/(19|20)\d\d/) >= 0)    {
                parts = field_obj.value.split("/");
                d = parseInt(parts[0]);
                m = parseInt(parts[1]);
                y = parseInt(parts[2]);

                //get the wrong dates
                if ((d>=30 && m==2) ||
                    (d==31 && (m==2 || m==4 || m==6 || m==9 || m==11)) ||
                    (d==29 && m==2 && !(((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0))))   {
                    alert("Please fill in valid " + field_name + "(dd/mm/yyyy)");
                    field_obj.focus();
                    return 0;
                }
                else
                    return 1;
            }
            else    {
                alert("Please fill in valid " + field_name + "(dd/mm/yyyy)");
                field_obj.focus();
                return 0;
            }
        }
		
		
        else if (field_type == TIME)    {
            if (field_obj.value.length == 5)    {
                parts = field_obj.value.split(":");
                if (parts.length == 2)  {
                    h = parts[0];
                    m = parts[1];
                    if (h>=0 && h<=23 && m>=0 && m<=59)
                        return 1;
                    else    {
                        alert("Please fill in valid " + field_name + "(hh:mm)");
                        field_obj.focus();
                        return 0;
                    }
                }
                else    {
                    alert("Please fill in valid " + field_name + "(hh:mm)");
                    field_obj.focus();
                    return 0;
                }
            }
            else    {
                alert("Please fill in valid " + field_name + "(hh:mm)");
                field_obj.focus();
                return 0;
            }
        }


        else if (field_type == DATETIME)    {
            parts = field_obj.value.split(" ");
            if (parts.length == 2)  {
                dates = parts[0];
                times = parts[1];
				
                if (dates.length == 10 &&
                    dates.search(/(0[1-9]|[12][0-9]|3[01])\/(0[1-9]|1[012])\/(19|20)\d\d/) >= 0)  {
                    dateparts = dates.split("/");
                    d = parseInt(dateparts[0]);
                    m = parseInt(dateparts[1]);
                    y = parseInt(dateparts[2]);

                    //get the wrong dates
                    if ((d>=30 && m==2) ||
                        (d==31 && (m==2 || m==4 || m==6 || m==9 || m==11)) ||
                        (d==29 && m==2 && !(((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0))))   {
                        alert("Please fill in valid " + field_name + "(dd/mm/yyyy hh:mm)");
                        field_obj.focus();
                        return 0;
                    }
                    else    {
                        //check time
                        timeparts = times.split(":");
                        if (timeparts.length == 2)  {
                            h = parseInt(timeparts[0]);
                            m = parseInt(timeparts[1]);
                            if (h>=0 && h<=23 && m>=0 && m<=59)
                                return 1;
                            else    {
                                alert("Please fill in valid " + field_name + "(dd/mm/yyyy hh:mm)");
                                field_obj.focus();
                                return 0;
                            }
                        }
                        else    {
                            alert("Please fill in valid " + field_name + "(dd/mm/yyyy hh:mm)");
                            field_obj.focus();
                            return 0;
                        }
                    }
                }
                else    {
                    alert("Please fill in valid " + field_name + "(dd/mm/yyyy hh:mm)");
                    field_obj.focus();
                    return 0;
                }
            }
            else    {
                alert("Please fill in valid " + field_name + "(dd/mm/yyyy hh:mm)");
                field_obj.focus();
                return 0;
            }
        }

        else
            return 1;
    }
}

function validate_sel(obj, fieldname) {
    if (obj.value == 0 || obj.value == "0" || obj.value == "")  {
        alert("Please select " + fieldname);
        obj.focus();
        return false;  
    } 
    else
        return true;
}

function checkValidDate(d, m, y, field_name)    {
    if ((d>=30 && m==2) ||
        (d==31 && (m==2 || m==4 || m==6 || m==9 || m==11)) ||
        (d==29 && m==2 && !(((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0))))   {
        alert("Please fill in valid Date for " + field_name);
        return 0;
    }
    else
        return 1;
}


function compareTimeString(time1, time2)    {
    //return 0 if time1 == time2
    //return 1 if time1 > time2
    //return -1 if time1 < time2
    if (time1 == time2)
        return 0;

    //split the time first
    time1part = time1.split(":");
    time2part = time2.split(":");

    time1_h = time1part[0];
    time1_m = time1part[1];
    time2_h = time2part[0];
    time2_m = time2part[1];

    //compare
    if (time1_h > time2_h ||
        (time1_h == time2_h && time1_m > time2_m))
        return 1;
    else
        return -1;
}


function compareDateString(date1, date2)    {
    //return 0 if time1 == time2
    //return 1 if time1 > time2
    //return -1 if time1 < time2
    if (date1 == date2)
        return 0;

    //split the time first
    date1part = date1.split("/");
    date2part = date2.split("/");

    date1_d = date1part[0];
    date1_m = date1part[1];
    date1_y = date1part[2];
    date2_d = date2part[0];
    date2_m = date2part[1];
    date2_y = date2part[2];

    //compare
    if ((date1_y > date2_y) ||
        (date1_y == date2_y && date1_m > date2_m) ||
        (date1_y == date2_y && date1_m == date2_m && date1_d > date2_d))
        return 1;
    else
        return -1;
}


function winpopup(url, win_width, win_height)  {
    sw = screen.width;
    sh = screen.height;

    x = Math.ceil((sw - win_width) / 2);
    y = Math.ceil((sh - win_height) / 2);
    window.open(url, "_blank", "left=" + x + ",top=" + y + ",menubar=no,scrollbars=yes,status=yes,resizable=yes,width=" + win_width + ",height=" + win_height);
}

function winpopup2(url, win_width, win_height)  {
    sw = screen.width;
    sh = screen.height;

    x = Math.ceil((sw - win_width) / 2);
    y = Math.ceil((sh - win_height) / 2);
    window.open(url, "_blank", "left=" + x + ",top=" + y + ",toolbar=yes,menubar=yes,scrollbars=yes,status=yes,resizable=yes,width=" + win_width + ",height=" + win_height);
}

function winpopup3(url, win_width, win_height)  {
    sw = screen.width;
    sh = screen.height;

    x = Math.ceil((sw - win_width) / 2);
    y = Math.ceil((sh - win_height) / 2);
    window.open(url, "_blank", "left=" + x + ",top=" + y + ",menubar=no,scrollbars=no,status=yes,resizable=no,width=" + win_width + ",height=" + win_height);
}

function winpopup4(url, win_width, win_height)  {
    sw = screen.width;
    sh = screen.height;

    x = Math.ceil((sw - win_width) / 2);
    y = Math.ceil((sh - win_height) / 2);
    window.open(url, "_blank", "left=" + x + ",top=" + y + ",menubar=no,scrollbars=yes,status=yes,resizable=no,width=" + win_width + ",height=" + win_height);
}

//restrict typing beyond maximum length. (used by textarea)
function restrict_length(obj, len)  {
    if (obj.value.length > len) {
        alert("Maximum Length Reach");
        obj.value = obj.value.substr(0, len);
    }
}