I'm developing web application in as.net and the most bizarre situation ocurred. in this application i am using only one aspx page ,When I select any item from dropdownliast then pageload is called again & again , and the dropdownliast_selectedomdexchanged method is called right after that. then page is loaded again , after selecting anything from downlist this task happens twice , But, unexpectedly, the Page_Load method of the Login page is also called! And strangest of all: the WebForm page is displayed.
how to resolve this problem??