Event.type  

// Prints the current event detected.
function OnGUI () {
    Debug.Log("Current event detected: " + Event.current.type);
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void OnGUI() {
        Debug.Log("Current event detected: " + Event.current.type);
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def OnGUI():
        Debug.Log(('Current event detected: ' + Event.current.type))