Here you can learn how to add client side validation on Browse/Upload button. JQuery helps a lot to add such type of client side validation on HTML DOM.
You can create form like below:
<form method="post" enctype="multipart/form-data" > <input id="browse_button" name="file" type="file"> <input type="submit" id="upload_file_btn" name="Submit" value="Upload File" /> </form>
Now you have to add following jQuery code insideĀ <head> tag.
<script type="text/javascript"> jQuery('document').ready(function(){ jQuery('#upload_file_btn').click(function(){ var browseButtonVal=jQuery('#browse_button').val().length; if(browseButtonVal<=0){ // Write code for what happen if file is not selected alert("Please upload file"); return false; }else{ // Write code for what happen if file is selected return true; } }); }); </script>
Note: You have to make sure that jQuery core fileĀ
is included in your <head> tag like below:
<script src="https://code.jquery.com/jquery-1.12.4.min.js" integrity="sha256-ZosEbRLbNQzLpnKIkEdrPv7lOy9C27hHQ+Xp8a4MxAQ=" crossorigin="anonymous"></script>

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