how to restrict or stop the same data provided in selection screen parameters its should stop fetch the data on previously provided data?

Hi Developer,

i have issues that i need stop or restrict the same entries provided in the selection screen parameters it should no display that data but it should give an alert message by saying the data all ready viewed or displayed.

example: organisation :getha pvt.td.

              name :ramesh.

              start date:10.2.2013.

these are parameter which has been displayed by clicking execute ,if provide the same value to display again it should give waring message.

Please guide me in solve the problem.

thanks.

ravi.