// email
function checkEmail (strng) {
var error="";
if (strng == "") {
   error = "Please enter your email address.\n";
}
    var emailFilter=/^.+@.+\..{2,3}$/;
    if (!(emailFilter.test(strng))) { 
       error = "Please enter a valid email address.\n";
    }
    else {
//test email for illegal characters
       var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/
         if (strng.match(illegalChars)) {
          error = "The email address contains illegal characters.\n";
       }
    }
return error;    
}

// phone number - check for 10 digit number
function checkPhone (strng) {
	var error = "";
	if (strng.length == 10) {
   	error = "Please enter 10 numbers.\n";
    }

	var illegalChars =/[^0-9]/;  //10 digit number only
    if (illegalChars.test(strng)) {
    error = "Please enter 10 numbers.\n";
    } 
return error;
}

// Message- spam check
function checkMessage (strng) {
var error = "";
if (strng == "") {
   error = "Please enter a message.\n";
}
	var illegalChars = /(bcc:)|(cc:)|(multipart)|(\[url)|(Content-Type:)|(\<a)|(http:)/i; //likely email phrases
    if (illegalChars.test(strng)) {
      error = "The message contains words or phrases that appear to be spam.\n";
    }  
    var spamChars = /(pharmacy)|(viagra)|(levitra)|(casino)|(poker)|(penis)/i; //likely spam
	if (spamChars.test(strng)) {
    error = "The message contains words or phrases that appear to be spam.\n";
    } 
return error;    
}    

// username - 4-50 chars, uc, lc
function checkRealName (strng) {
var error = "";
if (strng == "") {
   error = "Please enter your name.\n";
}
    var illegalChars = /[^a-zA-Z ]/; // allow only letters and numbers
    if ((strng.length < 4) || (strng.length > 50)) {
       error = "Please enter your name. Length 4 to 50 characters.\n";
    }
    else if (illegalChars.test(strng)) {
    error = "The name field contains illegal characters.\n";
    } 
return error;
}       

// exactly one radio button is chosen
function checkRadio(checkvalue) {
var error = "";
   if (!(checkvalue)) {
       error = "Please select someone to contact.\n";
    }
return error;
}