Javascript Validation

function validate(form_id,email) {  var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/; var address = document.forms[form_id].elements[email].value; if(reg.test(address) == false) {  alert('Invalid Email Address'); return false; }}<form id="form_id" method="post" action="action.php" onsubmit="javascript:return validate('form_id','email');">  <input type="text" id="email" name="email" />  <input type="submit" value="Submit" /></form>