my problem is like this i have two different application like on-screen keyboard and excel sheet in my problem i have: 1st application: form with number buttons. 2nd application: few forms with many texboxes in each. now i need to fill those text boxes with number using 1st application i want to how will 1st application know which text box of which form is having cursor and how will it send the data to it. i think it require knowledge of win32 api calls and all. which i very little idea. can u help me out in this . thanks in advance