function validateForm(theForm) {
	
	var reason = "";
	
	  reason += validateEmpty(theForm.First_Name);
	  reason += validateEmpty(theForm.Last_Name);
  	  reason += validateEmpty(theForm.Address);
  	  reason += validateEmpty(theForm.City);
	  reason += validateEmpty(theForm.State);
		reason += validateEmpty(theForm.Zip);
		reason += validateEmpty(theForm.Phone);
	  reason += validateEmpty(theForm.Email);
	  reason += validateEmail(theForm.Email);
	  
	  if (theForm.Phone.value != "") {
	  reason += validatePhone(theForm.Phone);
	  }
	      
	 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 "+fld.name+" 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)*@\w(\.?[-\w])*\.([a-z]{3}(\.[a-z]{2})?|[a-z]{2}(\.[a-z]{2})?)$/i;
    var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ ;
    
    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;
}


function validatePhone(fld) {
    var error = "";
    var stripped = fld.value.replace(/[\(\)\.\-\ ]/g, '');     

   if (fld.value == "") {
        error = "You didn't enter a phone number.\n";
        fld.style.background = 'Yellow';
    } else if (isNaN(parseInt(stripped))) {
        error = "The phone number contains illegal characters.\n";
        fld.style.background = 'Yellow';
    } else if (!(stripped.length == 10)) {
        error = "The phone number is the wrong length. Make sure you included an area code.\n";
        fld.style.background = 'Yellow';
    } 
    return error;
}