Swap - forcing Swap

[René L. Reingard]

hello,
today i see first time that the 'Systemmonitor' in a panel can be expanded  
into different branches, like Processor, RAM, Network, ... Ubuntu is  
allways new!
now i also see that the RAM (Pentium 3 with 256MB RAM) is allready with  
the simple desktop used to a high percentage (like 80%) and if greater  
processes are going on, RAM usage goes up that 100% (Cache then around 40  
to 60%).
BUT the Swap Partition is not used at all (in the beginning) and goes to a  
use of 25% after 15 minutes of heavy work (like Scanning the harddisk).

how the usage of the Swap can be forced - as the RAM is anyway allways  
used by around 80%.

thank you for answering,
regards,
René