Now we will learn how to add the Cells into the Worksheet.

For adding cells to a WritableSheet, first of all we have to create  a WritableSheet simply by importing the 
public interface WritableSheet which is contained in the jxl.write.WritableSheet.

 For adding a cell to a WritableSheet, firstly we create a WritableSheet as,
WritableSheet ws=workbook.createSheet("mysheet",0);

Then create any cell, say, a label we have created as,
Label lblName=new Label(0,0, "Name");

Then add this label cell by calling the addCell(WritableCell) method on the WritableSheet object as,
ws.addCell(lblName);
This adds a cell named Name to the sheet.