JS code popping up error

I got this below code from Google for E-mail validation in my js file.

function validateEmail(thefield) 
{  
   alert ('This is the 1st step');  
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;  
   alert ('This is the 2nd step');  **after this i am getting error in explorer**  
   var address = document.elements[thefield].value;   
   alert ('going into if loop' + address.value);  
   if(reg.test(address) == false)  
   {  
    alert('Invalid Email Address');   
 开发者_StackOverflow     return false;   
   }  
}

Please let me know what modifications are required in this to make it work??

HTML code:

<form action="pageserver" method="post" id="inputForm" target="_parent" onsubmit="return(onSubmit());">
 <input type="text" value=" " name="MIR-CLI-CNTCT-ID-TXT-T[1]" stype="Text" maxlength="50" onfocus="enterField(this)" onblur="validateEmail(this)" size="50" />

Thansk sdleihssirhc.

I could find out the error.... and fix it...

the line was having erros, var address = document.elements[thefield].value;

I removed the vairable which was passed in the function and just placed the same variable directly in the required field....

var address = document.all[email].value;