以下代码错误了.
function add_OnClick()
If DateDiff("d",mydate,form1.startday.value)< "7" Then
        MsgBox "申请日期超过当天日期7天,请重选"
        form1.startday.focus()
    Else    
        
        form1.submit
End If
<tr>
      <td width="216" class="td6" height="35">申请日期:</td>
     <td> <input onfocus="calendar()"  name="startday" type = "text" id="s2" >
      </td>
  </tr>

function add_OnClick()
If DateDiff("d",now(),mydate,form1.startday.value)<7 Then
        MsgBox "申请日期超过当天日期7天,请重选"
        form1.startday.focus()
    Else   
        form1.submit
End If
DateDiff返回的是数字类型

谢谢yms123,一针见血了.

呵呵~要细心啊~~