code: function format(vField, iLength, bCutFromFront) {
  		if (!vField) {
  			vField = vField === 0 ? "0" : "";
  		} else if (typeof vField === "number") {
  			var iField = vField;
  			vField = Math.round(vField).toString();
  			// Calculation of figures may be erroneous because incomplete performance entries lead to negative
  			// numbers. In that case we set a -1, so the "dirty" record can be identified as such.
  			if (vField.length > iLength || iField < 0) {
  				vField = "-1";
  			}
  		} else {
  			vField = bCutFromFront ? vField.substr(-iLength, iLength) : vField.substr(0, iLength);
  		}
  		return vField;
  	}
docs: format string to fesr compliant string