Issue with wordpress search

Hi ! I´m having a little problem with my wordpress theme. I have a search bar placed in the header and every time i click on the input field the page refreshes. How can i solve this ?

Here is my code:

<?php
require(TEMPLATEPATH . "/var.php");

if($df_logo) {
	if($df_logo == "Choose a logo:") { ?>
		<a><img src="<?php bloginfo('template_directory'); ?>/images/logo.png"></a><?php
	} else { ?>

		<a href=""><img src="<?php bloginfo('template_directory'); ?>/images/<?php echo $df_logo; ?>" /><?php
	}
} else { ?>
	</a><a href=""><img src="<?php bloginfo('template_directory'); ?>/images/logo.png"></a><?php
} ?>

</div>

  <form class="searchform" method="get" action="<?php bloginfo('url'); ?>/">
	<input type="text" value="search" name="s" class="searchinput" />

</form>