function getVendorPrefixedEventName(eventName) {
	  if (prefixedEventNames[eventName]) {
	    return prefixedEventNames[eventName];
	  } else if (!vendorPrefixes[eventName]) {
	    return eventName;
	  }

	  var prefixMap = vendorPrefixes[eventName];

	  for (var styleProp in prefixMap) {
	    if (prefixMap.hasOwnProperty(styleProp) && styleProp in style) {
	      return prefixedEventNames[eventName] = prefixMap[styleProp];
	    }
	  }

	  return '';
	}
Attempts to determine the correct vendor prefixed event name.

@param {string} eventName
@returns {string}