Check Image Extensions In FileUpload OnChange in C# JQuery

 Type The Below Query In ASPX page....

function checkFileExtension(elem) {

            var filePath = elem.value;

           

            var ext = filePath.substring(filePath.lastIndexOf('.') + 1).toLowerCase();

            var validExtensions;

            validExtensions = new Array();

            validExtensions[0] = 'jpg';

            validExtensions[1] = 'jpeg';

            validExtensions[2] = 'bmp';

            validExtensions[3] = 'png';

            validExtensions[4] = 'gif';

            for (var i = 0; i < validExtensions.length; i++) {

                if (ext == validExtensions[i])

                    return true;

            }

            alert('The file extension ' + ext.toUpperCase() + ' is not allowed!');

            elem.value = "";

            return false;

        }

 Type The Below Query In ASPX.CS page Load....

protected void Page_Load(object sender, EventArgs e)

{

ImageUpload.Attributes.Add("onchange", "return checkFileExtension(this);");

}