div.aboutstandard ul.aboutlist li {
    float: left;
    padding-left: 10px;
    padding-right: 10px;
    width: 300px;
    height: 280px;
}

div.aboutstandard ul.aboutlist li {
float: left;
padding-left: 10px;
padding-right: 10px;
width: 300px;
height: 280px;
}

When i am setting this dimensions for the height, it works perfectly in chrome and internet explorer, but in firefox it takes different dimensions. the text goes under the next image in firefox.

php code:

<ul class="aboutlist1">
         <li>
            <img class="aboutimg" src="images1.jpg" alt="<? $lang->text('ABOUT1'); ?>"/>

            <h1><? $lang->text('ABOUT1'); ?></h1>

            <p class="abouttext"><? $lang->text('ABOUT_TEXT1'); ?></p>
        </li>

        <li>
            <img class="aboutimg" src="images2.jpg" alt="<? $lang->text('ABOUT2'); ?>"/>

            <h1><? $lang->text('ABOUT2'); ?></h1>

            <p class="abouttext"><? $lang->text('ABOUT_TEXT2'); ?></p>
        </li>
       </ul>
<ul class="aboutlist">
        <li>
            <img class="aboutimg" src="image3.jpg" alt="<? $lang->text('ABOUT3'); ?>"/>

             <h1><? $lang->text('ABOUT3'); ?></h1>

            <p class="abouttext"><? $lang->text('ABOUT_TEXT3'); ?></p>
        </li>

        <li>
            <img class="aboutimg" src="image4.jpg" alt="<? $lang->text('ABOUT4'); ?>"/>

            <h1><? $lang->text('ABOUT4'); ?></h1>

            <p class="abouttext"><? $lang->text('ABOUT_TEXT4'); ?></p>
        </li>
</ul>