CSS div height not stretching

I'm programming a website and on a page I have dynamic content. To be specific I want to display some content in a div each. And the main div wont stretch upon this content.

#main{
    position:relative;
    background-image:url(images/main_middle.png);
    background-repeat:repeat-y; 
    width:850px;
    min-height:450px;
}
.intrebari{
    position:relative;
    width:400px;
    min-height:150px;
    padding:20px;
}

while($row=mysql_fetch_array($rezultat)){
    echo '开发者_StackOverflow<div class="intrebari">
                 <div id="upleft"></div>
         <div id="upright"></div>
         <div id="downleft"></div>
         <div id="downright"></div>
        '.$_SESSION['username'].' a intrebat:<br />
        '.$row['question'].'
         </div>';
}

What am I doing wrong?

---

The internal div has to be cleared so the outer should know the height of the inner div you may use a class

.clear{
  clear:both;
}

and introduce it after your inner div inside outer div main

echo '<div class="intrebari">
                 <div id="upleft"></div>
         <div id="upright"></div>
         <div id="downleft"></div>
         <div id="downright"></div>
        '.$_SESSION['username'].' a intrebat:<br />
        '.$row['question'].'
         </div><div class="clear"></div>';

this will help you

If you have given float to intrebari, you need to give float left or right to main div to get the main wrap the inner content

---

.intrebari{
    position:relative;
    width:100%
    min-height:150px;
    padding:20px;
}

if you want to have the content of the div.intrebari stretch horizontaly make the width of value to 100%