Hello,<BR><BR> I am doing a small calculation. I placed 2 textboxes, 2 required field validators, two range validators and 1 validation summary controls. After i enter the correct values in the textboxes and click button to display the result after small mathematical calculations. Upto this everything ok. First time, when i didnt enter required data its displaying the validation summary. Once the data is valid its diplaying the output. Then again i change the textbox values, validator control is showing error and summary. At the same time it also showing the result with previous values. <BR>I placed Page.IsValid in the button_click event. Still no change.<BR>What could be the problem?<BR><BR><BR>