Newbie problem

if (Greenfoot.mousePressed(this))

import greenfoot.*;

import java.util.List;
import java.util.ArrayList;

public class Cards extends Actor
{
    int x=87;
}

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

public class Deck extends Cards
{
    int cardsinhand=0;
    public void shift()
    {
    x=x+20;
    }
    public void drawcards()
    {
        getWorld().addObject(new Card(), x, 1680); 
        shift();
        cardsinhand++;
    }    
    public void act() 
    {
     if (Greenfoot.mouseClicked(this))
     {
        if (cardsinhand>=5)
        {
            drawcards();
        }
        else
        {
            for (int i=cardsinhand; i<5; i++)
            {
                drawcards();
            }
        }
     }
     } 
    }   

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

public class Senator extends Card
{
    public void shift()
    {
    x=x+20;
    }
    public void act() 
    {
     if (Greenfoot.mouseClicked(this))
     { 
      getWorld().addObject(new Senator(), x, 1680);
      shift();
     } 
    }
}