function btn_move(el, mouseLeft, mouseTop){
var leftRnd = (Math.random()-0.5)*20;
var topRnd = (Math.random()-0.5)*20;
var btnLeft = mouseLeft+(leftRnd>0?100:-100)+leftRnd;
var btnTop = mouseTop+(topRnd>0?30:-30)+topRnd;
btnLeft = btnLeft<100?(btnLeft+window.innerWidth-200):(btnLeft>window.innerWidth-100?btnLeft-window.innerWidth+200:btnLeft);
btnTop = btnTop<100?( btnTop+window.innerHeight-200):(btnTop>window.innerHeight-100?btnTop-window.innerHeight+200:btnTop);
el.style.position = 'fixed';
el.style.left = btnLeft+'px';
el.style.top = btnTop+'px';
}
function over_btn(e){
if(!e){
e = window.event;
}
btn_move(this, e.clientX, e.clientY);
}
document.getElementById('gbqfba').onmouseover = over_btn;