[hardwired]

always equals null
Move "wrdCnt++;" to the bottom of the loop. It is incrementing to the next (null) element before you get to the println statement.

Code:

//  <applet code="SA" width="400" height="200"></applet>
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.String.*;

public class SA extends Applet implements ActionListener
{
    TextField theSntnc = new TextField(60);
    Button pressMe=new Button("parse to array");
    String fillIt;
    String checkIt;
    Label fillMe;
    String[] sntncArray= new String[30];

    public void init()
    {
        System.out.println(getLayout().getClass().getName());
        setLayout(new BorderLayout());
        add(theSntnc, "North");
        add(pressMe, "South");
        pressMe.addActionListener(this);
    }

    public void actionPerformed(ActionEvent pressMe)
    {
        fillIt=new String (theSntnc.getText());
        fillMe=new Label("FillIt"+fillIt);
        add (fillMe);
        invalidate();
        validate();
        brkSntnc(fillIt);
        printArray();
    }

    public void brkSntnc(String sntnc)
    {
        int x=0;
        int wrdCnt=0;
        int myLen;
        while(x != -1)
        {
            myLen=sntnc.length();
            x=sntnc.indexOf(" ");
            if(x > -1)
                sntncArray[wrdCnt]=sntnc.substring(0, x);
            else
                sntncArray[wrdCnt]=sntnc;
            System.out.println("Before:"+sntnc);
            sntnc=sntnc.substring(x+1,myLen);
            System.out.println("After:"+sntnc);
            System.out.println("Array["+wrdCnt+"] is:"+sntncArray[wrdCnt]);
            wrdCnt++;
        }
    }

    private void printArray() {
        System.out.print("sntncArray = [");
        for(int j = 0; j < sntncArray.length; j++) {
            if(sntncArray[j] == null)
                continue;
            System.out.print(sntncArray[j]);
            if(j < sntncArray.length-1)
                System.out.print(", ");
        }
        System.out.print("]\n");
    }
}