The following function unselects (or deselects) all text on a web page. Include it in your Javascript and just call jQuery.unselectAll().
jQuery.unselectAll = function()
{
if (document.selection && document.selection.empty)
{
document.selection.empty();
}
else if (window.getSelection)
{
var sel= window.getSelection();
if(sel && sel.removeAllRanges)
sel.removeAllRanges();
}
}