java - Substitute command for ChildFieldEvent? -

i'm trying make interactive pdf form using itext , have used command:

pdfformfield personal = pdfformfield.createempty(writer);  personal.setfieldname("personal");  pdfptable table= new pdfptable(3);  pdfpcell cell;  cell= new pdfpcell();  cell.setcolspan(2);  textfield field = new textfield(writer, new rectangle(0,0),"name");  field.setfontsize(12); cell.setcellevent(new childfieldevent(personal, field.gettextfield(), 1)); table.addcell(cell); 

but it's showing

childfieldevent cannot resolved type

is there substitute command it?