try this:
char coords[50];
snprintf(coords,50,"lat=%s&long=%s&alt=%s&speed=%s&course=%s&date=%s&time=%s",lat,lon,alt,speed,vel,date,time);
edit: variable name
try this:
char coords[50];
snprintf(coords,50,"lat=%s&long=%s&alt=%s&speed=%s&course=%s&date=%s&time=%s",lat,lon,alt,speed,vel,date,time);
edit: variable name