多个输入框，可以对每个输入框是否输入字符进行有效的判断
脚本说明:
把如下代码加入<body>区域中
<script language="JavaScript">
<!--
function formCheck(formobj){
// Enter name of mandatory fields
var fieldRequired = Array("FirstName", "LastName");
// Enter field description to appear in the dialog box
var fieldDescription = Array("第一输入框", "第二输入框");
// dialog message
var alertMsg = "请把各个输入框都填全\n";
var l_Msg = alertMsg.length;
for (var i = 0; i < fieldRequired.length; i++){
var obj = formobj.elements[fieldRequired[i]];
if (obj){
switch(obj.type){
case "select-one":
if (obj.selectedIndex == -1 || obj.options[obj.selectedIndex].text == ""){
alertMsg += " - " + fieldDescription[i] + "\n";
}
break;
case "select-multiple":
if (obj.selectedIndex == -1){
alertMsg += " - " + fieldDescription[i] + "\n";
}
break;
case "text":
case "textarea":
if (obj.value == "" || obj.value == null){
alertMsg += " - " + fieldDescription[i] + "\n";
}
break;
default:
}
if (obj.type == undefined){
var blnchecked = false;
for (var j = 0; j < obj.length; j++){
if (obj[j].checked){
blnchecked = true;
}
}
if (!blnchecked){
alertMsg += " - " + fieldDescription[i] + "\n";
}
}
}
}
if (alertMsg.length == l_Msg){
return true;
}else{
alert(alertMsg);
return false;
}
}
// -->
</script>
<form name="formcheck" onsubmit="return formCheck(this);">
第一输入框: <input type=text name="FirstName" size="25"><br>
第二输入框: <input type=text name="LastName" size="25"><br>
<input type=submit value="提交">
</form>