function validate_form()
	{
		if(document.getElementById("email").value == "")
		 {
			alert("Please insert your email address");
			document.getElementById("email").select();
			return false;
			
		 }
		//email validation
		  if (document.getElementById('email').value != "")
			  {
				    var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
                    var address = document.getElementById('email').value ;
					
                 if(reg.test(address) == false)
				    {
					  alert('Invalid email address');
					  document.getElementById('email').select();
					  return false;
                     }
				  
		      }
	}