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

  reason += validateEmail(theForm.email);
  reason += validateName(theForm.name);
  reason += validateField(theForm.code);
  reason += validateComm(theForm.comments);
      
  if (reason != "") {
    alert("Some fields need correction:\n" + reason);
    return false;
  }

  return true;
}

function validateComm(fld) {
  var error = "";
  var iChars = "@#$%^&*+=-[]\/{}|\<>?";

  for (var i = 0; i < fld.value.length; i++) 
    {
      if (iChars.indexOf(fld.value.charAt(i)) != -1) 
  	{
  	  error = "The code field containts special characters. \n These are not allowed.\n Please remove them and try again.";
	  fld.style.background = 'Yellow';
  	}
    }	

    if (error != "") { } else  
    if (fld.value.length == 0) {
        fld.style.background = 'Yellow'; 
        error = "The code field has not been filled in.\n"
    } else {
        fld.style.background = 'White';
    }
    return error;  
}
function validateName(fld) {
  var error = "";
  var iChars = "!@#$%^&*()+=-[]\;,./{}|\":<>?";

  for (var i = 0; i < fld.value.length; i++) 
    {
      if (iChars.indexOf(fld.value.charAt(i)) != -1) 
  	{
  	  error = "The name field containts special characters. \n These are not allowed.\n Please remove them and try again.";
	  fld.style.background = 'Yellow';
  	}
    }	

    if (error != "") { } else    
    if (fld.value == "") {
        fld.style.background = 'Yellow'; 
        error = "Please enter your name.\n"
    } else {
        fld.style.background = 'White';
    }
    return error;
}

function validateField(fld) {
  var error = "";
  var iChars = "!@#$%^&*()+=-[]\;,./{}|\":<>?";

  for (var i = 0; i < fld.value.length; i++) 
    {
      if (iChars.indexOf(fld.value.charAt(i)) != -1) 
  	{
  	  error = "Containts special characters. \n These are not allowed.\n Please remove them and try again.";
	  fld.style.background = 'Yellow';
  	}
    }	

    if (error != "") { } else    
    if (fld.value == "") {
        fld.style.background = 'Yellow'; 
        error = "The message field has not been filled in.\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 = "Please enter a valid 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;
}