Unity 2D On Trigger Enter is not working, getting error

I am trying to get my game to switch scenes when i collide with a door entrance but i keep getting this error:

Assets/OnTriggerEnder2D.cs(4,14): error CS0101: The namespace global::' already contains a definition for ExampleClass’

With this code:

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
	public bool characterInQuicksand;
	void OntriggerEnter2D(Collider2D other) {
		characterInQuicksand = true;

The error you’re getting is telling you that a class with the name ExampleClass already exists, check your scripts and check the names of classes.

Also the method OntriggerEnter2D needs a capital T.