I have a FileUpload function in asp.net.

Below is my asp.net button.

1. <asp:FileUpload id="FileUpload1" runat="server" Width="150px"/>
2. <asp:Button id="btnUpload" runat="server" Text="Upload" onclick="btnUpload_Click" />

Which I can upload successful.

I try with asp validator but no luck.

2. <asp:RequiredFieldValidator ID="RequiredFieldValidator1"
3.     runat="server" ErrorMessage="Please upload your receipt." 
4.     ControlToValidate="FileUpload1" CssClass="alerttext"></asp:RequiredFieldValidator>

I need to validate whether if it's empty. If it's empty then alert user.

I have a img type button. The code are below.

1. <img name="Submit" type="image" onMouseOver="this.src='images/B_F_H.gif'" onMouseOut="this.src='images/B_F_L.gif'" onClick="validateField();" src="images/B_F_L.gif" width="105" height="32"/>

What I want to do is when clicked on this I need to validate the fileupload is not empty.

Below code I tried but no respond.

2. <script type="text/javascript">
3. function validateField()
4.     { 
5.         var imgVal = $('#FileUpload1').val(); 
6.         if(imgVal=='') 
7.        { 
8.             alert("empty input file"); 
9. 
   
10.         } 
11.         return false; 
12. 
    
13. }; 
14. </script>