How to show all product in a category page

In the magento 1.5 if you want to see all the product in a category in the same page then go to the
app\code\core\Mage\Catalog\Block\Product\List\Toolbar.php
find this line near line 228
// we need to set pagination only if passed value integer and more that 0
$limit = (int)$this->getLimit();

now chenge it
$limit = 0;

and it will work.