Table control with change data

Hi expert ,

I m using TC in program . i have 3 button 'Display' ' Change' 'Exit'.

when i click on display the data is display in table control . after that when i want to change selected row by open new form with field display in tab .but when i select a particular row for change new window is not open . i used "call screen 102 " after that but not working .

help me .

thanks ,

Ashish