为图片加alt的js代码

<mce:script language="JavaScript"><!-- var stylevar flag=false; function DrawImage(ImgD){ var image=new Image(); image.src=ImgD.src; if(image.width>0 && image.height>0){ flag=true; if(image.width/image.height>= 98/98){ if(image.width>98){ ImgD.width=98; ImgD.height=(image.height*98)/image.width; }else{ ImgD.width=image.width; ImgD.height=image.height; } ImgD.alt= "点击查看详细信息..."; } else{ if(image.height>98){ ImgD.height=98; ImgD.width=(image.width*98)/image.height; }else{ ImgD.width=image.width; ImgD.height=image.height; } ImgD.alt="点击查看详细信息..."; } }}// --></mce:script>