JS控制图片等比例缩放

function pimsize(imgname,widths,heights){

var w;

var h;

//window.alert(picimg.width);

//window.alert(picimg.height);

w=imgname.width;

h=imgname.height;

if(imgname.width>widths){

do

w=w-1;

while (w>widths) ;

s=w/imgname.width;

//window.alert(s);

imgname.width=w;

imgname.height=h*s;

h=imgname.height

}

//window.alert(imgname.height);

//window.alert(heights);

if(imgname.height>heights){

do

h=h-1;

while (h>heights) ;

s=h/imgname.height;

//window.alert(s);

imgname.width=w*s;

imgname.height=heights;

}

}

<a href='ProductDetail.asp?ID=<%=rs_proShow("id")%>&SortID=<%=rs_proShow("SortID")%>'><img src="<%=rs_proShow("smallPic")%>" onload="pimsize(this,180,140)" border="0" /></a>