remove columns from a tablemodel

hi everyone, I have a DefaultTableModel that I built with tableModel.addColumn("dasdasfasfs"), thereafter I fill it with addRow.
I want to reuse the tableModel, but before I want to clear it (rows and columns) to add different columns and different rows.

for the rows:
for (int i = 0; i < this.tableModel.getRowCount(); i++) {
this.tableModel.removeRow(i);
}

but don't know how to remove the columns :( and searched in the forum, but didnt find an answer

thanks

ok problem solved, use setColumnIdentifiers better than addColumn, it just replace columns