C# ,RDA.push clear old data at SQL server

Hi All,

On my PDA application RDA.push sends current rows to sql server 2005 , but the issue is the old rows allready exists on the sql server table at the PC side is deleted .

I don't know if this is the default of push command ? 

i'm using  SQLServerCE3.5 on PDA, SQL server 2005 and SQLserverCE angine 2.0 on PC.

Advise please.

Thanks

Hanadi