html form submission on different browsers
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I have this form set up to submit some text, the code below works perfectly for chrome, it allows the form to be submitted by pressing enter or clicking the button, but in firefox clicking the button or pressing enter does nothing, 

    <form id="form1" name="form1" method="get" action="main_results.php">
    	<input name="q" type="text" value="<?php echo $_GET['q']; ?>" size="67"/>
    	<input class="submit" type="button" value="Search" onclick="chkChecks()" />

Does anyone know what the problem is?