1) instead of storing username and password, you should store username and hash
PHP Code:
#define SALT "23kln50h2nasfjn0gn3021rnklsdfi9rhfwdf" //this is some random string, every server should edit it and use their own
new cache[512]
formatex(cache, sizeof(cache)-1, "%s%s%s", username, password, SALT)
new hash[34]
md5(cache, hash)
2) convert it to sql