//<!--
//---------------------------------------------------------------------------------------------------
function CheckMembershipNumber(formname, inputname) {
// Checks membership number for invalid characters - only digits are permitted
	var valid = false;
	document.forms[formname].elements[inputname].value = trim(document.forms[formname].elements[inputname].value);
	var inputvalue = trim(document.forms[formname].elements[inputname].value);
	inputvalue_re = new RegExp("^[0-9]+$", "g");

	// check for invalid characters
	if (inputvalue.length != 0){
		if (inputvalue.match(inputvalue_re)){
			valid = true;
		}else {
			alert("Invalid membership number: only digits permitted");
		}
	}

	return valid;
}
//---------------------------------------------------------------------------------------------------
function CheckRequiredFields(formname) {
// Checks mandatory fields have been entered. If not, displays message in input box
	var valid = true;
	var fieldnamelist = ["Title", "Forename", "Surname", "BuildingNumberAndStreet", "Town", "Postcode", "Country", "Email"]

	//alert("Title " + trim(document.getElementById("Title").value));
	
	// Loop over mandatory fields
	for ( var i = 0 ; i < fieldnamelist.length; i++){
		valid = CheckRequiredField(formname, fieldnamelist[i], valid);
	}
	return valid;
}
//---------------------------------------------------------------------------------------------------
function CheckRequiredField(formname, fieldname, valid) {
	// Checks mandatory field has been entered. If not, displays message in input box
	var inputvalue = trim(document.forms[formname].elements[fieldname].value)
	if (inputvalue.length == 0){
		document.forms[formname].elements[fieldname].value = "Input required"
		document.forms[formname].elements[fieldname].style.color = "red";
		valid = false;
	}
	return valid;
}
//---------------------------------------------------------------------------------------------------
function ClearField(formname, fieldname) {
	// Clears input required message from input box and resets text colour
	// If input required message is displayed, text colour will be red
	if (document.forms[formname].elements[fieldname].style.color == "red"){
		document.forms[formname].elements[fieldname].value = ""
		document.forms[formname].elements[fieldname].style.color = "black";
	}
	return;
}
//---------------------------------------------------------------------------------------------------
function trim(stringToTrim) {
	return stringToTrim.replace(/^\s+|\s+$/g,"");
}
//---------------------------------------------------------------------------------------------------
	function SubmitSearch(formname, inputfieldname, initialtextfieldvalue){
		var valid = true;
		var searchtext = document.forms[formname].elements[inputfieldname].value ;
		//  check that user has entered some search text
		if (searchtext.toLowerCase() == initialtextfieldvalue.toLowerCase() || searchtext == '' ){
			// if not, display error message.  Don't submit the form.
			alert('Error!! You need to enter some search text first - please try again');
			valid = false;
			document.forms[formname].elements[inputfieldname].value = initialtextfieldvalue;
		}else{
			document.forms[formname].submit();
		}
		return valid;
	}
//---------------------------------------------------------------------------------------------------
//-->