code: function _getTypeNumber(sText, nCorrectLevel) {			
  		var nType = 1;
  		var length = _getUTF8Length(sText);
  		
  		for (var i = 0, len = QRCodeLimitLength.length; i <= len; i++) {
  			var nLimit = 0;
  			
  			switch (nCorrectLevel) {
  				case QRErrorCorrectLevel.L :
  					nLimit = QRCodeLimitLength[i][0];
  					break;
  				case QRErrorCorrectLevel.M :
  					nLimit = QRCodeLimitLength[i][1];
  					break;
  				case QRErrorCorrectLevel.Q :
  					nLimit = QRCodeLimitLength[i][2];
  					break;
  				case QRErrorCorrectLevel.H :
  					nLimit = QRCodeLimitLength[i][3];
  					break;
  			}
  			
  			if (length <= nLimit) {
  				break;
  			} else {
  				nType++;
  			}
  		}
  		
  		if (nType > QRCodeLimitLength.length) {
  			throw new Error("Too long data");
  		}
  		
  		return nType;
  	}
docs: Get the type by string length
  
  @private
  @param {String} sText
  @param {Number} nCorrectLevel
  @return {Number} type