JS去除首尾空格（同VBS的Trim)

function trim(inputString) {
   
              if (typeof inputString != "string") { return inputString; }
              var retValue = inputString;
              var ch = retValue.substring(0, 1);
              while (ch == " ") {
           //檢查字符串開始部分的空格
                  retValue = retValue.substring(1, retValue.length);
                  ch = retValue.substring(0, 1);
              }
              ch = retValue.substring(retValue.length-1, retValue.length);
              while (ch == " ") {
                 //檢查字符串結束部分的空格
                 retValue = retValue.substring(0, retValue.length-1);
                 ch = retValue.substring(retValue.length-1, retValue.length);
              }
              while (retValue.indexOf("  ") != -1) {
          //將文字中間多個相連的空格變為一個空格
                 retValue = retValue.substring(0, retValue.indexOf("  ")) + retValue.substring(retValue.indexOf("  ")+1, retValue.length);
              }
              return retValue;
           }

//-->
</script>