Web Forms :: Restrict Content Selection From Webpage?

On my web page i have to restrict content selection if user drag mouse on page, as on normal page have enable that if user try to drag mouse then content will get select.

I have found javascript for same and apply it, its running well for IE and i have found css tag for Mozzila to restrict content selection, both working well,but now what i want , on my web page i have textboxes, due to apply JS and CSS user also can't able to select text from textbox..and i want to allow to select content from textbox.

window.onload = function () {
document.onselectstart = function () { return false; } // ie
}
CSS
Body
{
-moz-user-select:none; // Mozzila
}