Delete (Reverse Backspace) Button

I have built a delete button in Android, just like in Windows, which removes the string on the right hand side of the cursor (one by one). (Instead of the mainstream Backspace which removes the left side.)

Tell me if you have any better ideas.

package com.example.app;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.text.Editable;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView.BufferType;
import android.widget.Toast;

public class MainActivity extends Activity {
    public Toast t, t1,t2;
    Editable a, b, d, f, a1;
    String e;
    public int c, d1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final EditText ed;

        Button dlt;

        dlt = (Button) findViewById(R.id.button1);

        ed = (EditText) findViewById(R.id.editText1);
        ed.clearFocus();

        dlt.setOnClickListener(new OnClickListener() {
            @SuppressLint("NewApi")
            public void onClick(View v) {

                InputMethodManager mgr = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                boolean check = mgr.isActive(ed);
                if(check==true){

                    Toast.makeText(getApplicationContext(), "Welcome", t2.LENGTH_SHORT)
                    .show();
                }
                a = ed.getEditableText();

                b = a;
                c = ed.getSelectionStart();

                String a11 = b.toString().substring(c);
                Toast.makeText(getApplicationContext(), a11, t1.LENGTH_SHORT)
                        .show();
                String a22 = b.toString().substring(0, c);

                boolean daj = b.toString().isEmpty();
                if (a11 != null && !a11.trim().equals("")) {

                    int strChar = a11.length();
                    String strcut = a11.substring(1, strChar);
                    e = a22.concat(strcut);

                    ed.setText(e, BufferType.EDITABLE);
                    b = ed.getEditableText();
                    ed.setSelection(c);
                } else {
                    Toast.makeText(getApplicationContext(), "Cool",
                            t.LENGTH_SHORT).show();
                }

            }

        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}