submitForm=function() {
 
 var sender_name = document.forms[0].name.value.length;
 var sender_message = document.forms[0].message.value.length;
 
 if(sender_name == 0) {
	 
  alert('Please enter your name.');	 
  return;
  
 }
 
 if(sender_message == 0) {
	 
  alert('Please enter a message.');	 
  return;
  
 }
 
 document.forms[0].submit();

}

window.onload=function() {

 document.getElementById('send').onclick=function(){submitForm();}
 
}