public void toPounds(View view){
    EditText amount = (EditText)findViewById(R.id.amount);

    Double omrAmount = Double.parseDouble(amount.getText().toString());

    Double gbrAmount = omrAmount * 1.79;

    Toast.makeText(getApplicationContext(), "£" + gbrAmount.toString(), Toast.LENGTH_LONG).show();
}

public void toRiyals(View view){
    EditText amount = (EditText)findViewById(R.id.amount);

    Double gbrAmount = Double.parseDouble(amount.getText().toString());

    Double omrAmount = gbrAmount / 1.79;

    Toast.makeText(getApplicationContext(), omrAmount.toString() + " Riyals", Toast.LENGTH_LONG).show();
}