mask for brazillian cellphone. NOT TESTED YET!

gistfile1.js

function mascara(field,callback){
        v_obj=field;
        v_fun=callback;
        setTimeout("executeMask()",1)
    }

    function executeMask(){
        v_obj.value=v_fun(v_obj.value);
    }

    function maskPhone(valueField) {
        valueField = valueField.replace(/\D/g,"");

        var firstNumber = "";
        var ddd = "";
        var isNineDigits = false;
        var lengthCellActual = valueField.length;

        if (valueField.length > 2) {
          ddd = valueField.substring(0,2);
          firstNumber = valueField.substring(2,3);
        }

        if (ddd == 11) {
          if (firstNumber == 6 || firstNumber == 7 || firstNumber == 8 || firstNumber == 9 ) {
              isNineDigits = true;
              v_obj.setAttribute("maxlength","15");
            } else {
              v_obj.setAttribute("maxlength","14");
            }
        } else {
          v_obj.setAttribute("maxlength","14");
        }

        valueField = valueField.replace(/^(\d{2})(\d)/g,"($1) $2");

        if (lengthCellActual == 7) {
          if (!isNineDigits) {
            valueField = valueField.replace(/(\d)(\d{1})$/,"$1-$2");
          }
        } else if (lengthCellActual == 8) {
          if (!isNineDigits) valueField = valueField.replace(/(\d)(\d{2})$/,"$1-$2");
          else valueField = valueField.replace(/(\d)(\d{1})$/,"$1-$2");
        }  else if (lengthCellActual == 9) {
          if (!isNineDigits) valueField = valueField.replace(/(\d)(\d{3})$/,"$1-$2");
          else valueField = valueField.replace(/(\d)(\d{2})$/,"$1-$2");
        } else if (lengthCellActual == 10) {
          if (!isNineDigits) valueField = valueField.replace(/(\d)(\d{4})$/,"$1-$2");
          else valueField = valueField.replace(/(\d)(\d{3})$/,"$1-$2");
        } else if (lengthCellActual == 11) {
          valueField = valueField.replace(/(\d)(\d{4})$/,"$1-$2");
        }

        return valueField;
    }