I have the following form which sends data to a php file. The php file deletes a complete remote ftp. this may take a while, so i want to show a loading image. The output of the php file is in an iframe.

Here is the code:

<form action="del.php" id="form" method="post" target="output"  >
	Server: <input type="text" name="server_id" value="" />
	Name:<input type="text" name="name" value="" />
	Password:<input type="password" name="password" value="" /> <br>  
	Create Log? <input type="checkbox" name="log" value="" />
	Output list of files? <input type="checkbox" name="out" value="" /><br>
	<input type="submit"  name="delete" value="Delete FTP!" /></td><br>

        <div id="loading_image"><img src="image.gif" /></div>
	<iframe id="output" ></iframe>
I know, that I have to use some Javascript but I do not have any experience with it! I tried a lot of different ways after searching by Google but nothing worked!

Can anybody help me solving this problem?

Best regards and sorry for the bad English