Thanks for your Reply,
 we are using .NET  web application. the problem is solved in one screen.  but if i use same key function in other object then it is not working.
today i have  faced one more problem.
i have recorded the script to selected a category from dropdown box. i got error message when i play it again. it is showing  like " There are several objects in the system that match the recognition attributes of the "tableMaintable" mapped object". how can i over come this.
Error from Log
There are several objects in the system that match the recognition attributes
of the "tableMaintable"
mapped object.
This may cause the "Object not found" error.
Objects
Sys.Process("iexplore").Page("http://10.10.1.217/PR009A/MainPage.aspx").Form("f1").Table(0).Cell(1,
0).Table(0).Cell(0,
1).Frame("AppBody").Frame("bodyFrame").Form("f1").Table("tab1")
Sys.Process("iexplore").Page("http://10.10.1.217/PR009A/MainPage.aspx").Form("f1").Table(0).Cell(1,
0).Table(0).Cell(0,
1).Frame("AppBody").Frame("bodyFrame").Form("f1").Table(0)
To solve the problem, you may need to modify mapping
settings for the "tableMaintable"
object or one of its parent objects.