javascript - Append canvas to document body using JS -

i trying add canvas html document such in position 0,0 , overlayed above other elements. i've done research , means, think doing right thing:

canvas.style.position = "absolute"; canvas.style.left = "0px"; canvas.style.top = "0px"; canvas.style.zindex = "100"; body.appendchild(canvas); 

however, canvas appears @ bottom of document, rather @ top left corner, above elements. absolute position , setting coordinates should trick, no?

simply add new div before content , target so

<div class="canvas-placement"> </div> 

jquery

canvas.style.position = "absolute"; canvas.style.left = "0px"; canvas.style.top = "0px"; canvas.style.zindex = "100"; $('.canvas-placement').append(canvas);