function a(i){
		b(i);
	}
	function b(i){
		switch(i){
			case 1:
			document.getElementById("jis").style.display="block";
			document.getElementById("jis1").style.display="none";
			break;
			case 2:
			document.getElementById("jis").style.display="none";
			document.getElementById("jis1").style.display="block";
		}
	}



<!-- 
// 说明：用 JavaScript 实现网页图片等比例缩放 
function DrawImage(ImgD,FitWidth,FitHeight) 
{ 
var image=new Image(); 
image.src=ImgD.src; 
if(image.width>0 && image.height>0) 
{ 
if(image.width/image.height>= FitWidth/FitHeight) 
{ 
if(image.width>FitWidth) 
{ 
ImgD.width=FitWidth; 
ImgD.height=(image.height*FitWidth)/image.width; 
} 
else 
{ 
ImgD.width=image.width; 
ImgD.height=image.height; 
} 
} 
else 
{ 
if(image.height>FitHeight) 
{ 
ImgD.height=FitHeight; 
ImgD.width=(image.width*FitHeight)/image.height; 
} 
else 
{ 
ImgD.width=image.width; 
ImgD.height=image.height; 
} 
} 
} 
} 
//-->