First error is that you have defined a class of .texter but you have used an id in the html
You should use semantic markup for your header which would really be an h1. You have a div with an id of hdr and then some break tags and then a nested div if .texter and then more break tags and then p tags.
This what you have:
and it could be simplified to this.
<div id="hdr"><img src="http://www.rodoslovlje.com/beliorao/images/shd_headcoa1.gif" alt="White Eagle" /> <div id="texter"><p> <br />Српско хералдичко друштво "Бели Орао"<br /></p></div> </div>
The line-height:100px will ensure the text is central withn the 100px high div ( as long as you don't want the text to wrap etc)
Hope that helps