Writing conditional logic via CSS

Sometimes we face some UI problem like for example We need a line break in Internet Explorer 7. But we don't need that for other browser. This can be done in many ways but i got a interesting solution of this. write a CSS like this

.breakOnlyInIE7
{
 display:none;
 *display:block;
}

and write a new line html code like below

<br class="breakOnlyInIE7" /> 

That is our very known <br /> tag with a CSS class containing IE7 specific CSS Hack. The above code will render <br /> tag only in IE7 and for rest of the browser no new line tag will be rendered! ;)