function trim(stringToTrim) {
    return stringToTrim.replace(/^\s+|\s+$/g, "");
}
function ltrim(stringToTrim) {
    return stringToTrim.replace(/^\s+/, "");
}
function rtrim(stringToTrim) {
    return stringToTrim.replace(/\s+$/, "");
}


/*动态调整frame的高度*/
var getFFVersion=navigator.userAgent.substring(navigator.userAgent.indexOf("Firefox")).split("/")[1]   
//extra height in px to add to iframe in FireFox 1.0+ browsers   
var FFextraHeight=getFFVersion>=0.1? 16 : 0    
function dyniframesize(iframeid) {
  var pTar = null;
  if (document.getElementById) {
    pTar = document.getElementById(iframeid);
  } else {
    eval('pTar = ' + iframeid + ';');
  }
  if (pTar && !window.opera) {
    //begin resizing iframe
    pTar.style.display="block";
    if (pTar.contentDocument && pTar.contentDocument.body.offsetHeight) {
      //ns6 syntax
      pTar.height = pTar.contentDocument.body.offsetHeight+FFextraHeight;
    } else if (pTar.Document && pTar.Document.body.scrollHeight) {
      //ie5+ syntax
      pTar.height = pTar.Document.body.scrollHeight;
    }
  }
}

/*
计算带中文的字符串的长度，一个中文字算2个字节，一个英文算一个字节
*/
function strlen(str) {
  var len = 0;
  var i;
  for (i=0;i<str.length;i++) {
    if (str.charCodeAt(i)>255) len+=2; 
    else len++;
  }
  return len;
}