function checkRequired(form_name) {

	

	failed = false;

	

	if (document.forms[form_name].required.value) {

		reqArray = document.forms[form_name].required.value.split(",");



		for (a = 0; a < reqArray.length; a++) {

			if(document.forms[form_name].elements[reqArray[a]].value == "") {

				document.forms[form_name].elements[reqArray[a]].className = "textfield-required";

				if (!failed) { document.forms[form_name].elements[reqArray[a]].focus(); }

				failed = true;

			} else {

				document.forms[form_name].elements[reqArray[a]].className = "textfield-ok";

			}

		}



		if (failed) {

			alert("One or more required fields were not filled in. Please fill in all the required fields before submitting.\nThe required fields are highlighted.");

			return false

		}

	}



	return true;

}



function checkPosition(form_name) {

	

	var failed = false;

	

	var elements = parseInt(document.forms[form_name].elements.length) - 3;

	var max_pos = elements;

	var positions = new Array(elements - 1);

	

	for(var i = 0; i < elements; i++) {

		var curr_pos = document.forms[form_name].elements[i].value;

		if ((!isNumeric(curr_pos)) || (parseInt(curr_pos) > max_pos) || (parseInt(curr_pos) < 1) || (curr_pos == "")) {

			document.forms[form_name].elements[i].className = "textfield-required";

			if (!failed) { document.forms[form_name].elements[i].focus(); }

			failed = true;

		} else {

			var duplicate = false;

			for(j = 0; j < positions.length; j++) {

				if (parseInt(positions[j]) == parseInt(curr_pos))

					duplicate = true;

			}

			

			if (duplicate) {

				document.forms[form_name].elements[i].className = "textfield-required";

				if (!failed) { document.forms[form_name].elements[i].focus(); }

				failed = true;

			} else {

				document.forms[form_name].elements[i].className = "textfield-ok";

				positions[i] = parseInt(curr_pos);

			}

		}

	}

	

	if (failed) {

		alert("The proposed item order is invalid. Check fields highlighted in red for:\n- non-numeric values;\n- numeric values less than 1;\n- numeric values larger than the maximum number of items;\n- duplicated numeric values.")

		return false;

	}

	

	return true;	

}



function checkEmail(str) {

	var emailFilter=/^.+@.+\..{2,3}$/;

	if (!(emailFilter.test(str))) { return false; }



	var illegalChars= /[\(\)<>,;:\\\/"\[\]]/;

	if (str.match(illegalChars)) { return false; }



	return true;

}



function checkValidNick(str) {

	var legalChars = /^[-a-z _]+$/i;

	if (str.match(legalChars)) { return true; } else { return false; }

}



function checkValidDate(str) {

	var regexp = /^\d{4}\-\d{2}-\d{2} \d{2}:\d{2}:?\d{0,2}$/;

	if (!(regexp.test(str))) { return false; } else { return true; }

}