Validate Coupon Codes with Javascript

Question

I am trying to get the code below to work. If i enter in the correct coupon code it still give me the "Sorry, The Coupon Code you entered is invalid. Please check and try again!" message.

Here is the javascript code:

<script language = "javascript"> 
function validate(coupon) { 
codes = new Object();
codes.GOLD20 = 20;
codes.GOLD = 30;
codes.GOLD40 = 40;
codes.GOLD50 = 50;

if (codes[coupon]) 
 { 
 window.alert("Coupon Code Accepted! Click the Order button!"); 
 } 
else 
 { 
 window.alert("Sorry, The Coupon Code you entered is invalid. Please check and try again!"); 
 } 
} 
</script>

Here is the html:

<input type="text" name="text1"> 
<input type="button" value="Validate Coupon" name="Submit" 
    onclick="validate()">` 

If you see any errors in my code please let me know or if you you know why i am not getting the alert for the Coupon code accepted please let me know.

Answer 1

It's because your no value is passed to validate. When you click, validate() gets called, with no parameter, so coupon is undefined.

The HTML should be:

<input type="text" name="text1"> 
   <input type="button" value="Validate Coupon" name="Submit" 
   onclick="validate(document.getElementsByName('text1')[0].value)">

Live JSFiddle Demo