// general fields
function checkField(strng) {
var error="";
var invalidChars= /[\(\)\<\>\?\*\+\$\%\#\~\|\;\:\\\"\[\]]/;

if (strng.length == 0) {
   error = "Please enter a contact name.\n";
}
else if (strng.match(invalidChars)) {
          error = "The data you have entered contains invalid characters.\n";
       }
return error;    
}

// email
function checkEmail(strng) {
var error="";
var emailFilter=/^.+@.+\..{2,3}$/;
var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/;

if (strng.length == 0) {
   error = "Please enter a contact email address.\n";
}
if (!(emailFilter.test(strng))) { 
       error = "Please enter a valid email address.\n";
    }
    else if (strng.match(illegalChars)) {
          error = "The email address contains illegal characters.\n";
       }
return error;    
}

// phone number - strip out delimiters and check for 10 digits
function checkPhone(strng) {
var error = "";

var invalidChars= /[\<\>\?\*\$\%\#\~\|\;\:\\\"\[\]]/;

if (strng.length == 0) {
   error = "Please enter a contact phone number.\n";
}
else if (strng.match(invalidChars)) {
          error = "The data you have entered contains invalid characters.\n";
       }

    else if (!(strng.length < 20)) {
	error = "The phone number is the wrong length. Make sure you included an area code.\n";
    } 
return error;
}