Formula needed to receive negative response for multiple columns

[CJGunner87]

Sorry my Title might be misleading! Here is what I'm looking for. In column D is the date a vehicle is request to be used from in column H is the registration for the vehicle that will be used. I want column m to tell me if that registration input in column H is already in use for the date in column D based on all the dates already in column D and all the registrations already in column H. I apologize if I'm not making any sense if I could wrap my head around this by myself I wouldn't need to post here haha. thanks for any help y'all can give

 

[BenMiller]

Put this in M1 and drag down.

=IF(SUMPRODUCT(($D:D=D2)*(H:H=H2))>1,"Yes","No")

 

[CJGunner87]

Put this in M1 and drag down.

=IF(SUMPRODUCT(($D:D=D2)*(H:H=H2))>1,"Yes","No")

Thank you for that that's awesome! Unfortunately I’m only me half way their. Thisworkbook has macros that allow me to create a list of registration numbers andselect multiple of those from that list in one cell. How would I figure thisinto that formula so It’ll see both those registrations and tell me if one isalready assigned for that date?