如果文本框(First_Name)为空,我会尝试出错。例如,如果 firstname 字段留空,用户将收到以下错误:“请输入您的名字”但是当我在将字段留空后单击提交按钮时没有任何反应...
<HTML>
<HEAD>
<TITLE>this is a test page</TITLE>
<script language="javascript" type="text/javascript">
<!--
function CheckForm()
{
var formObj = document.getElementById("Data");
var firstname = formObj.FIRST_Name.value;
if(notEmpty(firstname, "Please enter your first name")){
return true;}
return false;
}
function notEmpty(elem, helperMsg){
if(elem.value.length == 0){
alert(helperMsg);
elem.focus(); // set the focus to this input
return false;
}
return true;
}
</script>
</HEAD>
<BODY>
<div style="background: #CCCC99">
<HR><FORM id="Data" onsubmit="return CheckForm()" >
<P>First Name: <input type=text name=FIRST_Name maxlength=15 size=15>
</P>
<input type=submit value="Submit Products Registration Form" style="width: 220px"><input type=reset value="Reset">
</form>
</div>
</BODY>
</HTML>