Here's one i found, it's pretty self explanatory.
::Catch Any Pokemon (L+R) (Select)
:::Press L+R, you will get 649 Master Ball and 100 Ultra Ball, Toss to change amounts to Pokemon number and level respectively. Press Select before heading into grass.
94000130 FCFF0000
02233FAC 02890001
02233FB0 00640002
D2000000 00000000
94000130 FFFB0000
DA000000 02233FAE
D3000000 00000000
D7000000 02250010
D3000000 00000000
DA000000 02233FB2
D3000000 00000000
D7000000 02250012
D3000000 00000000
D9000000 02250010
D3000000 00000000
C0000000 0000002F
D6000000 02250010
D2000000 00000000
I've personally used this a lot and it works perfectly for me i'm currently using the Aus Version of Black which is identical to the US Version so you shouldn't have any problems.