var img_true_size = function(image){ // get Image true size var w = image.width , h = image.height ; if ( typeof image.naturalWidth !== 'undefined' ) { // for Firefox, Safari, Chrome alert('Firefox, Safari, Chrome Firefox, Safari, Chrome'); w = image.naturalWidth; h = image.naturalHeight; } else if ( typeof image.runtimeStyle !== 'undefined' ) { // for IE alert('IE IE IE IE IE IE'); var run = image.runtimeStyle; var mem = { w: run.width, h: run.height }; // keep runtimeStyle run.width = "auto"; run.height = "auto"; w = image.width; h = image.height; run.width = mem.w; run.height = mem.h; } else { // for Opera alert('Opera Opera Opera Opera Opera'); var mem = { w: image.width, h: image.height }; // keep original style image.removeAttribute("width"); image.removeAttribute("height"); w = image.width; h = image.height; image.width = mem.w; image.height = mem.h; } return {width:w, height:h}; }