I want to delete the white space in product details. How can find this code in php?

Thanks

Those <br/> 's come from the Virtuemart Core files. You need to open the core VM files to remove them. Modifying the Virtuemart Core is beyond our support, we don't provide support about Virtuemart itself.

but you can try to include some CSS rules something like;

.divClassGoesHere {
margin-top:-10px;
}

As I am seeing, you are using "Firebug" so it should be easy for you to find the class name to apply the CSS rules.
I am sure, this negative 10pixel would be enough to eliminate the space (that caused by the unnecessary <br/>)

Regards.
Support