devexpress and webmodalanchor

[tomorrow_ft]

hi, I am using an aspxbutton and webmodalanchor for opening a new pop up page.I am opening the page but when I want to close the page, the page is being closed two times.I think the page loading two times If I use an aspxhyperlink the page, is being closed normally.But ı want to use aspxbutton. Thanks..