show related products in product view page in magento

go to catalog.xml file and search below code

<reference name="content">
<block type="catalog/product_view" name="product.info" template="catalog/product/view.phtml">



insert related block after that block type:-

<block type="catalog/product_list_related" name="catalog.product.related" as="related" template="catalog/product/list/related.phtml"/>

</reference>

set this function in view.phtml file
<?php echo $this->getChildHtml('related'); ?>