// valid selector from dropdown list
	function checkDropdown(selchoice, vFieldName) {
	var error = "";
	    if (selchoice == "") {
	    error = "Please select a " + vFieldName + " from the drop-down list.\n";
	    }    
	return error;
	} 
	
	// non-empty textbox
	function isEmpty(strng, vFieldName) {
	var error = "";
	  if (strng.length == 0) {
	     error = vFieldName + " is a required field.\n";
	  }
	return error;	  
	}
	
	//valid e-mail address
	function checkEmail (strng) {
	var error="";
	if (strng == "") {
	   error = "Email is a required field.\n";
	}
	else
	{
		var emailFilter=/^.+@.+\..{2,3}$/;
		if (!(emailFilter.test(strng))) { 
		   error = "Please enter a valid email address.\n";
		}
		else {
		//make sure email has no illegal characters
			var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/
			 if (strng.match(illegalChars)) {
			  error = "The email address contains illegal characters.\n";
		   }
		}
	}
	return error;    
	}
	
	// make sure phone number is valid
	function checkPhone(strng, numDigits, name) {
		var error = "";
		var stripped = strng.replace(/[\(\)\.\-\ ]/g, ''); 
		if(stripped == "")
		{
			error = name + " is a required field.\n";
		}
		else if(isNaN(parseInt(stripped))) {
			error = name + " contains illegal characters.\n";
		}
		else if(!(stripped.length == numDigits)) {
			error = name + " is the wrong length.\n";
		}
		return error;
	}