ERROR in my applet program

Question

When I execute my applet, it gives me this error:
Exception in thread "main" java.lang.NoSuchMethodError: main
However when it runs in the appletviewer fine. Heres the code:
import java.applet.Applet;
import java.awt.*;
import javax.swing.*;
public class slideshow extends Applet implements Runnable
        //creates the main thread
     Thread mainthread=null;
     //the amount of sleep time for the thread
     int time=2000; //milliseconds
        int x=1;
        int numberofimages=5; //this variable is needed since the paint function will know how many
        private Image bgimage1;
        private Image bgimage2;
        private Image bgimage3;
        private Image bgimage4;
        private Image bgimage5;
        String parameter;
     public void init()
                parameter = getParameter("totalimages");
                int numimages = (parameter==null? 0:Integer.parseInt(parameter));
                numberofimages=numimages;//setting the global to this value
                String imagename = getParameter( "name" );
                String imagename2 = getParameter( "name2" );
                String imagename3 = getParameter( "name3" );
                String imagename4 = getParameter( "name4" );
                String imagename5 = getParameter( "name5" );
                bgimage1=getImage(getDocumentBase(), imagename);
                bgimage2=getImage(getDocumentBase(), imagename2);
                bgimage3=getImage(getDocumentBase(), imagename3);
                bgimage4=getImage(getDocumentBase(), imagename4);
                bgimage5=getImage(getDocumentBase(), imagename5);
          //constructs the thread
          mainthread=new Thread(this);
          //starts the thread
          mainthread.start();
    public void run(){
          while(mainthread!=null)
                {try{
              //makes the thread sleep
              mainthread.sleep(time);
          catch(Exception e){}
          //repaints the applet
          repaint();
    public void stop()
          if(mainthread!=null){mainthread.stop();}
    public void paint(Graphics g)
            if (x==1)
               g.drawImage(bgimage1,0,0,getWidth(),getHeight(),this);
               //draws image the full size of the applet
            if (x==2)
               g.drawImage(bgimage2,0,0,getWidth(),getHeight(),this);
            if (x==3)
               g.drawImage(bgimage3,0,0,getWidth(),getHeight(),this);
            if (x==4)
               g.drawImage(bgimage4,0,0,getWidth(),getHeight(),this);
            if (x==5)
               g.drawImage(bgimage5,0,0,getWidth(),getHeight(),this);           
            x++;
            if (x>numberofimages)
               x=1; 
//end     
}     

Answer 1

When you say "execute" do you mean you are trying to launch your Applet as an application like:
java slideshow
That won't work because your code is only an Applet. When you invoke a class with the java.exe command, you need a main method and your code doesn't have one. You'll also need to explicitly call init() and run(), and you'll need to provide a Frame to hold your Applet.