I need help with first time longjump tips!!

i really need help with my longjumps. i dont know if it is my strafes or prestrafe or whatever. i get very low longjump distances and i need help.
heres a demo of me trying to longjump.

http://www.mediafire.com/?mhs9iym2lhcj302

there are some longjump tutorials in youtube etc. just practice.