Question

having some trouble trying to figure this out, complete novice when it come to JavaScript. I’m trying to validate a form, more specific the expiry date of a credit card.
e.g jan 2011 would be invalid but dec 2011 would be valid etc.
This is what i have so far:

function ExpiryDate() {

var year
var months

today = new Date();
    expiry = new Date(year, month);
    if (today.getTime() > expiry.getTime())

    return false;
else
    return true;
};

my form reads:

<form id="myform" method="post" action="default.html" onsubmit="return Validate(this);">

<p>Expiration Date: Month

<select name="ExpMon" id="ExpMon" title="select a month"> 
        <option value="1">Jan</option> 
        <option value="2">Feb</option> 
        <option value="3">Mar</option>
        <option value="4">Apr</option> 
        <option value="5">May</option> 
        <option value="6">June</option> 
        <option value="7">July</option> 
        <option value="8">Aug</option> 
        <option value="9">Sept</option> 
        <option value="10">Oct</option> 
        <option value="11">Nov</option> 
        <option value="12">Dec</option> 
 </select>      

 Year:
 <select name="ExpYear" id="ExpYear" title="select a year"> 
     <option value="2010">2010</option> 
     <option value="2011">2011</option> 
     <option value="2012">2012</option> 
     <option value="2013">2013</option>
     <option value="2014">2014</option> 
     <option value="2015">2015</option>
</select></p> 

</form

I’m not to sure how to use the id’s to get what I want, any help would be appreciated, thanks in advance. note:I have a function called Validate which validates a text field in my form so i could attach it to this somehow.

Answer 1

var year = document.getElementById("ExpYear").value;
var month = document.getElementById("ExpMon").value;

If you prefer, you can use the names instead; you’d have to get Validate to pass the form element in as a parameter, but then you can use theForm.ExpYear.value and theForm.ExpMonth.value.

Note: many people dislike statements of the form if (today.getTime() > expiry.getTime()) return false; else return true; when you can simply write return today.getTime() <= expiry.getTime();.