you can do it like this

Code:
var ja[10];
...
i=0;
while (i<10) // another thing: This has to be i<10 not i<=10
{
   ja[i] +=a;
   i++;
}


you could also do it with for(){} ...but this should work, too

but in your first code:
if(a == 0) [...] ja1 += a; [...] - does this really make sense?!

and be a bit careful...
the first var in this array is ja[0] - not ja[1]

POTATO-MAN saves the day! - Random