How to Use Find Method in Table & Form Level

Hi,
1)How to use Find Method in Table Level.

public void modifiedField(fieldId _fieldId)

{
;
super(_fieldId);
switch(_fieldId)
{
case fieldNum(Cust_new,AccountNum) :
{
this.Name = CustTable::find(this.AccountNum).Name;
}
break;
}
}

2.How to use find Method in form Level

Form->DS->Field->modified()
public void modified()
{
CustTable ct;
;
super();

Cust_new.Name = CustTable::find(Cust_new.AccountNum).Name;
// Or we can use following code
//ct = CustTable::find(Cust_new.AccountNum);
//Cust_new.Name = ct.Name;
}