script08.js

图灵程序设计丛书 JavaScript基础教程源代码

window.onload = initForm;

function initForm() {
	var allTags = document.getElementsByTagName("*");

	for (var i=0; i<allTags.length; i++) {
		if (allTags[i].className.indexOf("reqd") > -1) {
			allTags[i].onblur = fieldCheck;
		}
	}
}

function fieldCheck() {
	if (this.value == "") {
		this.style.backgroundColor = "#FFFF99";
		this.focus();
	}
	else {
		this.style.backgroundColor = "#FFFFFF";
	}
}