function validateForm()  
{ 
  var numericExpression = /^[0-9]+$/;
 with (document.callback) 


 {
  if (name.value=="") 
  { 
    alert("Please enter your first name."); 
	name.style.background = 'Yellow';
	return false;
  } 
  if (lname.value=="") 
  { 
 	alert("Please enter your last name."); 
	lname.style.background = 'Yellow';
	lname.focus() 
	 return false;
  } 
  
	if (phone.value == "") 
		{
        alert("Please enter a contact number");
		phone.style.background = 'Yellow';
		phone.focus() 
	    return false;
    	} 
		
	if (isNaN(parseInt(phone.value))) 
		{
        alert("Please enter numbers only in Contact Number field");
		phone.style.background = 'Yellow';
		phone.focus() 
	    return false;
    	} 
	
	if ((phone.value.length < 10) || (phone.value.length > 11)) 
		
		{0
        alert("Please enter a full UK Phone Number with out using spaces");
		phone.style.background = 'Yellow';
		phone.focus() 
	    return false;
    	} 

  
 else
  { 

  return true; 
  submit();
  }  
} 
}