image download

gistfile1.js

var imgs = document.querySelectorAll('a[href*="jpg"], a[href*="gif"], a[href*="png"]');

for(var i=0;i<imgs.length;i++) {
	dispatchMouseEvents({ type:'click', altKey:true, target:imgs[i], button:0 });
}

function dispatchMouseEvents(opt) {
	var evt = document.createEvent('MouseEvents');
	evt.initMouseEvent(opt.type, opt.canBubble||true, opt.cancelable||true, opt.view||window, 
	                   opt.detail||0, opt.screenX||0, opt.screenY||0, opt.clientX||0, opt.clientY||0, 
	                   opt.ctrlKey||false, opt.altKey||false, opt.shiftKey||false, opt.metaKey||false, 
	                   opt.button||0, opt.relatedTarget||null);
	opt.target.dispatchEvent(evt);
	return evt;
}