function validate()
{
   if ((isEmpty(document.feedback.email.value)) || (isEmpty(document.feedback.comments.value)) || (isEmpty(document.feedback.comments.value)))
   {
     alert("All fields are required. Please complete all fields.");
	 document.feedback.name.focus();
	 return false;
   }	 
   invalidCharsList = " /:,;~#!";
	    if (document.feedback.email.value.indexOf('@',0)== -1 ||
	        document.feedback.email.value.indexOf('@',0)== 0 ||
	        document.feedback.email.value.indexOf('.',0)== -1) {
	        alert("Error! \n\nThe email address you entered appears to be invalid! \n\nPlease re-enter your email address and try again.");   
	        document.feedback.email.select();
	        document.feedback.email.focus();
	        return false;
	   }
	    for (i = 0; i < invalidCharsList.length; i++) {
	        errorChar = invalidCharsList.charAt(i);
	        if (document.feedback.email.value.indexOf(errorChar,0) != -1) {
	            alert("Error! \n\nThe email address you entered appears to be invalid! \n\nPlease re-enter your email address and try again.");
		        document.feedback.email.select();
	            document.feedback.email.focus();
	            return false;
	        }
	    }
}

function isEmpty(data)
{
	   for (var i=0; i<data.length; i++){
	      if(data.substring(i, i+1) != " ")
	         return(false);
	   }
	   return(true);
}