// JavaScript Document

function validateFormOnSubmit(theForm) {
var reason = "";

  reason += validateUsername(theForm.name);  
  reason += validateEmail(theForm.email);
  
  
      
  if (reason != "") {
    alert("Some fields need correction:\n" + reason);
    return false;
  }
  
  return true;
} 

function validateEmpty(fld) {
    var error = "";
 
    if (fld.value.length == 0) {
        fld.style.background = 'Yellow'; 
        error = "The required field has not been filled in.\n"
    } else {
        fld.style.background = 'White';
    }
    return error;  
}
function validateUsername(fld) 
{
    var error = "";
    var illegalChars = /\W/; // allow letters, numbers, and underscores
 
    if (fld.value == "") 
		{
			fld.style.background = 'Yellow'; 
			error = "You didn't enter your name.\n";
		} 
	
	else 
		{
			fld.style.background = 'White';
    	}
    return error;
}
function trim(s)
{
  return s.replace(/^\s+|\s+$/, '');
}
function validateEmail(fld) {
    var error="";
    var tfld = trim(fld.value);                        // value of field with whitespace trimmed off
    var emailFilter = /^[^@]+@[^@.]+\.[^@]*\w\w$/ ;
    var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ ;
   
    if (fld.value == "") {
        fld.style.background = 'Yellow';
        error = "You didn't enter an email address.\n";
    } else if (!emailFilter.test(tfld)) {              //test email for illegal characters
        fld.style.background = 'Yellow';
        error = "Please enter a valid email address.\n";
    } else if (fld.value.match(illegalChars)) {
        fld.style.background = 'Yellow';
        error = "The email address contains illegal characters.\n";
    } else {
        fld.style.background = 'White';
    }
    return error;
}