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 = "O campo email precisa ser preenchido.\n";
    } else if (!emailFilter.test(tfld)) {              //test email for illegal characters
        fld.style.background = 'Yellow';
        error = "Por favor, digite um email válido.\n";
    } else if (fld.value.match(illegalChars)) {
        fld.style.background = 'Yellow';
        error = "O email contém caracteres ilegais..\n";
    } else {
        fld.style.background = 'White';
    }
    return error;
}

function validateEmpty(fld, fld_label) {
    var error = "";

    if (fld.value.length == 0) {
        fld.style.background = 'Yellow';
        error = "O campo "+fld_label+" precisa ser preenchido.\n"
    } else {
        fld.style.background = 'White';
    }
    return error;
}