var randomlinks=new Array()

randomlinks[0]='<img alt="" src="global-images/top-main-heart.jpg">'
randomlinks[1]='<img alt="" src="global-images/top-main-bear.jpg">'
randomlinks[2]='<img alt="" src="global-images/top-main-rabbit.jpg">'
randomlinks[3]='<img alt="" src="global-images/top-main-texture.jpg">'

function randomlink(){
var add = randomlinks[Math.floor(Math.random()*randomlinks.length)]
return(add)
}

document.write( randomlink() );