application catch/ history is not getting clear automatically for new version of application + GWT application

1. hosted GWT application in IIS. 

2. browse the application IE.

<div>3. modified the application.</div> <div></div> <div>4. Now hosting it again on IIS in same directory with same name n all.</div> <div></div> <div>5. IE is showing old version only until I explicitly clears the history nall through IE.</div>