有关跳出警告框的问题

Question

<script>
function chk(){
   if(document.form1.t1.value==""){
      alert("warning!!!!");
   }
}
</script>
<form name=form1>
<input name=t1 type=textbox value="" onblur=chk()>
</form>

Answer 1

<script language="vbScript">
<!--
function form1_onsubmit()
d=document.getElementsByTagName("input")
for i=0 to document.getElementsByTagName("input").length-1
if (document.getElementsByTagName("input")(i).type="text") and (document.getElementsByTagName("input")(i).value="") then
alert("有空的text")
form1_onsubmit=false
end if
nextend function
//-->
</script>
<form name=form1>
<input name=t1 type=textbox value="">
<input type="text" name="">
<input type="submit">
</form>