Master Page and Childpage layout is auto changed, like absolute position

Hello,
I have problem is very confuse to solution and its fatal for me. I have an ASP.Net application then all of displayed page is changed like absolute layout caused one of childpage. It start when I have a childpage with table for locate button then I Inadvertent draged that button, like this :

And after that, all another childpage page with master page is changed and broken, like this :


Please help me, are this ASP.NET Issue this very confusing all changed caused one child page and all of application layout is broken.
Hope Your answer,
Mafullah