Adding two possitive numbers results a negative?

Hello everybody. I have a strange problem that it's racking my brain! i have the following codefor (int i=0;i<ascii.length;i++){

int randNum=rand.nextInt(100000000);

buffer[i]=randNum*256+ascii[i];

}

(ascii is an array of four integers that picture an ascii characters).

Normaly that would result a buffer full of positive numbers.In my case thats not always true. Many times i get as a result a negative number even if the other two numbers that i add are positive. What's wrong here? Thanks in advance!>

[711 byte] By [skywritera] at [2007-10-3 11:22:27]