在html頭中加入以下3句話,可以防止大部分浏覽器緩存 < meta http-equiv ="pragma" content ="no-cache" >
< meta http-equiv ="Cache-Control" content ="no-cache, must-revalidate" >
< meta http-equiv ="expires" content ="Wed, 26 Feb 1997 08:21:57 GMT" > 或者js中加入類似下面的代碼,讓每次的連結都不一樣 var s=Math.random()*10;
document.getElementById( "checkCodeImg").innerHTML= "<img src='/checkcode.jsp?rnd="+s+ "'/>";