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 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;

}



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;

}



function validateFormOnSubmit(theForm) {

var reason = "";





  reason += validateEmail(theForm.from);

  reason += validateEmpty(theForm.name);







      

  if (reason != "") {

    alert("Some fields need correction:\n" + reason);

    return false;

  }



  return true;

}





function validateContact(theForm) {

var reason = "";





  reason += validateEmail(theForm.from);

  reason += validateEmpty(theForm.name);

  reason += validateEmpty(theForm.phone);





      

  if (reason != "") {

    alert("Some fields need correction:\n" + reason);

    return false;

  }



  return true;

}