how to check image behaviuor
<p>here is my image width and size code which is work perfectly but problem is that when i pass null fileupload it give me error 'argument not valid ' but i want pass null value also how will i do</p>

<pre><code>HttpPostedFile fil = this.FileUp.PostedFile;
                 System.Drawing.Image uploadimage = System.Drawing.Image.FromStream(fil.InputStream);
                 if (uploadimage.Height &gt; 155 || uploadimage.Width &gt; 124)
                 {
                     lblErrorMsg.Visible = true;
                     lblErrorMsg.Text = "&lt;font class='orange'&gt;Height and width not accpetable&lt;/font&gt;";
                     return;

                 }
</code></pre>
