Error : object reference is not set to instance of an object

[Dillo]

Hi,

I get the following error when using the Sipek Softphone trying to
send the DTMF using dial_Dtmf function in the SDK.this is function
return "NULL".

Please correct me, am i going to rigth direction.?

ICallProxyInterface Dtmf_Dial;
Dtmf_Dial.dialDtmf("1",EDtmfMode.DM_Outband);

Thanks
Dillo