Get item from combobox using axapta code

display str telNo()
{
telNo=CustTable::find(Table1.ParentOffice).Phone;
Table1.TelNo = telNo;
rec = ComboBox1.selectionChange();
officeName = ComboBox1.getText(ComboBox1.selectionChange());
parentOffice1 = Table1.ParentOffice;
return CustTable::find(CustTable.AccountNum).Phone;

}