Floating Layer - While Scrolling - The Layer Flickers Continuously

I have created a floating layer using Javascript that remains always on top of page on scrolling.Issue is,at some point while scrolling,the layer flickers continuously.

The html page is as follows:

Many common software systems, JavaScript has a history of security problems. Many of these problems could allow a person with malevolent intent to steal sensitive information from a visitor. The number and type of such holes in security vary among browsers and operating system versions. Most JavaScript security holes have been caught and fixed, but new ones are being discovered all the time. For a list of current security holes check out your browser's and operating system's Web pages. As a Web site author, it is your responsibility to keep up-to-date on the current status of known security holes in the applications you create.

Signing Scripts. In Chapter 11, I explained that JavaScript does not provide the ability to directly access files on the client computer. This can be a very large hurdle to overcome if you're trying to upload a file to a server from the client computer. Fortunately, file uploading is one of many functional enhancements that signed scripts provide. Signed scripts are specially packaged scripts that have been verified and signed to be correct and non-threatening. These scripts have additional rights on the client computer that allow a programmer to do many things that he wouldn't otherwise be able to.

With the introduction of Netscape 4.0, a new security model was put in place that would allow digitally signed scripts to bypass some of the restrictions that had previously been placed on them. A signed script can request expanded privileges from the visitor and, with the visitor's permission, gain access to restricted data. A signed script requests these additional permissions through LiveConnect, which allows your JavaScript code to communicate with the Java Capabilities API. The security model allows JavaScript to access certain classes in Java in order to extend its functionality while still maintaining tight security for the client.

A digital signature is a fingerprint of the original programmer, and it allows the security model of the browser to detect where (or from whom) it originated. A script signer can be a person or an organization. By signing a script, you acknowledge yourself as the author and accept responsibility for the program's actions. A signed script contains a cryptographic checksum, which is just a special value that ensures the signed script has not been changed. When a digital signature is detected, you are assured that the code has not been tampered with since the programmer signed it.

Once you finish writing a script, you can use the Netscape Signing Tool to digitally sign it. Signing a script does the following:

Unambiguously assigns ownership of the script to a person or organization.

Allows an HTML page to use multiple signed scripts.

Places the signed script into a Java Archive (JAR) file.

Places the source of the script in the JAR file.

Once a user confirms the origin of the script and is assured that it has not been tampered with since its signing, he or she can then decide whether to grant the privileges requested by the script based on the validated identity of the certificate owner and validated integrity of the script.

JAVASCRIPT FILE IS AS FOLLOWS:

AND CSS FILE IS AS FOLLOWS:

At some point while scrolling,the div 'movable' flickers continuously,while at some other point,it is perfectly stable.