获取客户端的cookie

function getCookie(c_name){

if(document.cookie.length>0){
c_start = document.cookie.indexOf(c_name+'=');
if(c_start != 1){
c_start = c_start + c_name.length+1;
c_end = document.cookie.indexOf(";", c_start);
if(c_end == -1){
c_end = document.cookie.length;
}
return unescape(document.cookie.substring(c_start, c_end));
}
}
return "";
}