Code to control the size of a picture in a Web page _javascript

1, with the mouse drag to change the size
<script language= "JavaScript" >
function Resizeimage (evt,obj) {
Newx=evt.x
Newy=evt.y
Obj.width=newx
Obj.height=newy
}
</script>

2, with the mouse scroll control picture size

3, the picture label in the code control size
screen.width-500) this.style.width= screen.width-500; " >

4, CSS control picture size
1. CSS2 Direct implementation: img{max-width:500px;} (ie temporarily does not support)
2. Expression implementation: Img{width:expression (width>500?) 500px ": width);} (IE only)
3. Use JS. Method: Using document.getElementsByTagName ("IMG") method to get all the IMG elements traversing the IMG element to judge its width and do the appropriate operation