JavaScript: ImageClick through transparent iframe -

i have transperent iframe, created next js function:

frames.prototype.createiframe = function (framename, frwidth, frheight, zindex) {     var frameobj = document.createelement('iframe');     frameobj.width = px(frwidth);     frameobj.src = 'content.htm';     frameobj.height = px(frheight);     frameobj.id = framename;     frameobj.name = framename;     frameobj.frameborder = 0;     frameobj.allowtransparency = 'allowtransparency';     frameobj.style.zindex = zindex;     frameobj.style.position = 'absolute';     frameobj.style.scrolling = 'no';     frameobj.style.scroll = 'no';     frameobj.style.overflow = 'hidden';     frameobj.style.left = px(0);     frameobj.style.top = px(0);     globalclass.appendchild(window, frameobj); } 

below iframe images placed. created event handlers these images. example document.getelementbyid("myimage").onclick(alert("click!"));

if run ie, works fine. run chrome, firefox, opera nothing works. how can correct this? upper transparent iframe has event handlers , works in ie also.

document.getelementbyid("myimage").onclick= function(){ 

alert("click!"); }