Standing Up

Hey guys,
I have been surfing for about a year (although have wanted to for about 10) and I am currently having a few issues!
I have managed to get the hang of a lot but when I try to pop-up my leading leg dosen't get into the correct position so I end up surfing on my back leg and front knee!! It is really frustrating and wondered if anybody had any tips on how to improve and stop my 'lazy leg'?
Cheers
I have been surfing for about a year (although have wanted to for about 10) and I am currently having a few issues!
I have managed to get the hang of a lot but when I try to pop-up my leading leg dosen't get into the correct position so I end up surfing on my back leg and front knee!! It is really frustrating and wondered if anybody had any tips on how to improve and stop my 'lazy leg'?
Cheers