【www.gdgbn.com--php函数】

function strlen(str) {
 return (is_ie && str.indexof("n") != -1) ? str.replace(/r?n/g, "_").length : str.length;
}

function mb_strlen(str) {
 if(typeof page_charset == "undefined" ){
  page_charset = is_ie ? document.charset : document.characterset;
 }
 var lengthi = 0;
 for(var i = 0; i < str.length; i++) {
  lengthi += str.charcodeat(i) < 0 || str.charcodeat(i) > 255 ? (page_charset == "utf-8" ? 3 : 2) : 1;
 }
 return lengthi;
}

function mb_strcut(str, maxlength, dot) {
 var len = 0;
 var res = "";
 var dot = !dot ? "..." : "";
 maxlength = maxlength - dot.length;
 for(var i = 0; i < str.length; i++) {
  len += str.charcodeat(i) < 0 || str.charcodeat(i) > 255 ? (page_charset == "utf-8" ? 3 : 2) : 1;
  if(len > maxlength) {
   res += dot;
   break;
  }
  res += str.substr(i, 1);
 }
 return res;
}

本文来源：http://www.gdgbn.com/jiaocheng/27751/