css:
.block_header{ padding:0; margin:0 auto; width:984px;}
.logo { float:left; padding:0; margin:0; width:278px;}
.search { float:right; padding:55px 25px 0 0; margin:0; width:194px;}
.search form{ display:block; float:right; padding:0;}
.search span{ display:block; float:left; background:url(images/search_bg.gif) left top no-repeat; padding:0 3px; width:149px; height:33px;}
.search form .keywords{ line-height:14px; float:left; border:0; width:153px; padding:9px 0; margin:0; background:none; font:normal 14px Arial, Helvetica, san-serif; color:#9c9c9c;}
.search form .button { padding:0; margin:0; float:left;}
HTML:
<div class="block_header">
<div class="logo">
<a href="#">
<img src="images/logo.gif" border="0" alt="logo">
</a>
</div>
<div class="search">
<form id="form1" name="form1" method="post" action="">
<label>
<span>
<input name="q" type="text" id="textfield" class="keywords" maxlength="50" value="search...">
</span>
<input name="b" type="image" src="images/search.gif" class="button">
</label>
</form>
</div>
</div>
block_header的高度为零。block_header中只有LOGO时是有高度的，但是加上search后高度就变成0了 百思不得其解 求教
