Using pull downs and calc birthdate

coolecho · 04-21-2010, 03:42 AM

Hello,

I am trying to use select options to get birthdate and calculate the age. I got the birthday with "birthDay = document.form1.selDate;" However i'm lost on the birthMonth and birthYear. I've looked at lots of examples. The birthMonth probably needs to be converted to integer, or use 1 thru 12 rather than Jan thru Dec. But birthYear i'd think would come back as a valid number. Is anyone familiar with this?

Thanks.

Code:

<html>
<head>
<title>Main</title>
<script language="javascript">
<!--
function Age()
{
    var birthDay;
    var birthMonth;
    var birthYear;
    var userAge;
    var currentDay = new Date();
    var dayNow = currentDay.getDate();
    var monthNow = (currentDay.getMonth());
    var yearNow = (currentDay.getFullYear());

    birthDay = document.form1.selDate;
    
    // Don't know how to get birthmonth????
//  birthMonth = (parseInt(document.form1.selMonth.value)-1);
    
    birthYear = document.form1.selYear;
    // alert("birthyear " + birthYear); ( gives "birthYear [object HTMLSelectElement]")

    if((monthNow > birthMonth)||(monthNow == birthMonth & dayNow >= birthDay))
    { userAge = birthYear; }
    else {    userAge=birthYear+1;}
    alert("As of today, " + currentDay +' \n'+", you are: " + (yearNow - userAge) + " years old");
}
//-->
</script>
</head>
<body>
<form name="form1" id="startOfForm">
<table><tbody>
    <tr>
        <td class="question"><label for="birthdate">Enter Birthdate</label></td>
        <td>
            <select name=selMonth>
            <option value=0 selected>Month</option>    <option selected value="Jan">Jan</option>
            <option selected value="Feb">Feb</option> <option selected value="Mar">Mar</option>
            <option selected value="Apr">Apr</option> <option selected value="May">May</option>
            <option selected value="Jun">Jun</option> <option selected value="Jul">Jul</option>
            <option selected value="Aug">Aug</option> <option selected value="Sept">Sept</option>
            <option selected value="Oct">Oct</option> <option selected value="Nov">Nov</option>
            <option selected value="Dec">Dec</option>
            </select>
            <select name=selDate>
            <option value=0 selected>Date</option> <option selected value="1">1</option>
            <option selected value="2">2</option> <option selected value="3">3</option>
            <option selected value="4">4</option> <option selected value="5">5</option>
            <option selected value="6">6</option> <option selected value="7">7</option>
            <option selected value="8">8</option> <option selected value="9">9</option>
            </select>
            <select name=selYear>
            <option value=0 selected>Year</option> <option value="2001">2001</option>
            <option value="2000">2000</option> <option value="1999">1999</option>
            <option value="1998">1998</option> <option value="1997">1997</option>
            <option value="1996">1996</option> <option value="1995">1995</option>
            </select>
        </td>
    </tr>
    <tr>
        <td>
        <input name="cmd" type=button value="Age"
                onclick="Age()" style="width:150px; height:30px;">
        </td>
    </tr>
</tbody></table>
</form>
</body>
</html>

Dormilich · 04-21-2010, 04:02 AM

as a Rule of Thumb, anything you get from a form control is a string, so you have to take care if you use the + operator (it is used for addition and string concatenation).

you can make your life easier in the month case:

PHP Code:


			
<select name="selMonth">
    <option value="0">Jan</option>
    <option value="1">Feb</option>
    <option value="2">Mar</option>
// ...
</select>

in the end, you just define a new Date object.

PHP Code:


			
var day  = document.form1.selDate.value;
var mon  = document.form1.selMonth.value;
var year = document.form1.selYear.value;
var Birthday = new Date(year, mon, day);

after that you only need to calculate the year portion out of the Date difference.

jmrker · 04-21-2010, 04:33 AM

Or check your other forum submissions ... see: http://www.webdeveloper.com/forum/sh...d.php?t=228388

coolecho · 04-21-2010, 03:18 PM

Hello,

Sorry about the cross post. The .value worked great, and changing month selects to numbers as well.

thanks