It is possible to print only the elements that are being put within a <div>...</div>.. actually I already wrote a simple code to hide a certain section on the page to be hidden when printed but it looks like there is other code that overwrite it and it will appear when I print it. The code run well on some of my forms but other it won't work and I expect it has been overwritten..i guess..

So, I'm just thinking to print only the things that I want instead of hiding some parts. any advice how this can be done?

my code to hide when print:

<style type="text/css" media="print">
.no_print{
display:none;
}
</style>

That is the approach, yes.