How can I change the heap size and the stack size of tomcat 5 server?

Heap size is changed by using the option:

-Xmxn

Here n is the size to be defined. This Specifies the maximum size of the memory allocation pool. This value must be greater than 1000 bytes. To modify the meaning of n, append either the letter k for kilobytes or the letter m for megabytes. The default value is 64m. The upper limit for this...