calcultate distance between zip codes

[ripken204]

okay im doing one of those sites where you have to find the closest places within so and so miles, that part i have done. where i need help now is a select statement for mysql. i have no clue how to calculate the distance between 2 spaces if i am given both places longitude and latitude. anyone know a formula for this that is for a select statement?

[bubbisthedog]

I Googled 'longitude latitude calculation sql' and it returned several valuable results on the first page of results.

[ripken204]

ya i did that too and i found only 1 that seems to work. for some zip codes it works perfectly, for others, not so much. i wonder how accurate the database is that i have.