I have created a form. Associated with the form there are different buttons for different actions when they are invoked. Now a user clicked a button on the form to invoke a particular action. Before the required process takes place after invoking the button the user changed his mind and clicked another button, thus halting the previous process. As my design of the forms goes, it allows the user to do so. But i want to design my form in such a way that user cannot take back his action . How can I do it. That is when once a user invokes a button, his attempt to invoke the other button while the processing for previous button's action taking place must not happen.