Need help in in radio button in gridview

Question

Hi all, Thru radio button i am selecting the data from gridview. Here all radio buttons are selectable at a time. Actually it should not happen at a time user can select only one button which i could not do. My second problem is when i am selecting particular radiobutton that details should be displayed in text box. I have Itemid, ItemName, Quantity, Rate and Total field in gridview. These values i have inserted thru textbox so i have all the corresponding text box for all. So once i select particular radiobutton those details should be displayed in corresponding textbox. I have done the insertion coding for this but couldn't do selecting thru radiobutton and dispalying in textbox. Pls somebody help me in coding for this problem. Thanks, sumit