<script language="javascript">
function checkedNull()
{
if (fm.ch.value=="")
{
alert("警告");
return false;
}
else
{
return true;
}
}
</script>
<form name="fm" method="post" onsubmit="javascript:return checkedNull()">
<input type=text name="ch">
<input type=submit onclick="this.form.action='a.asp';" value="确定">
<input type="button" onclick="javascript:return checkedNull()" value="试用">
</form>
function checkedNull()
{
if (fm.ch.value=="")
{
alert("警告");
return false;
}
else
{
return true;
}
}
</script>
<form name="fm" method="post" onsubmit="javascript:return checkedNull()">
<input type=text name="ch">
<input type=submit onclick="this.form.action='a.asp';" value="确定">
<input type="button" onclick="javascript:return checkedNull()" value="试用">
</form>
var str;
function s_value(str1)
{
str=str1;
}
function check()
{
alert(str);
}
</script>
<form name=form method=post action="third.php" onsubmit="return check()">
<input type="image" onclick="s_value('第一个按钮')" name=jump src="pic/jump.jpg">
<input type="image" onclick="s_value('第二个按钮')" name=nextstep src="pic/next.jpg">
</form>