//if you want to require one of them
if(trim($_REQUEST['username']) || $_REQUEST['date'] || $_REQUEST['employee'])
{

$dbhost = "localhost";
$dbuser = "root";
$dbpass = "p4ssw0rd";
$dbname = "webcall";
        //Connect to MySQL Server
mysql_connect($dbhost, $dbuser, $dbpass);
        //Select Database
mysql_select_db($dbname) or die(mysql_error());
        // Retrieve data from Query String


$where="";

$query = "SELECT * FROM LS_webcall";
if(trim($_REQUEST['username'])
	$where.= " and webcall_username='" . mysql_real_escape_string($_REQUEST['username']) ."' ");

if(trim($_REQUEST['date'])
	$where.= " and `webcall_date='" . mysql_real_escape_string($_REQUEST['date']) ."' ");

if(trim($_REQUEST['employee'])
	$where.= " and webcall_employee='" . mysql_real_escape_string($_REQUEST['employee']) ."' ");

$query.= trim($where, ' and');

$qry_result = mysql_query($query) or die(mysql_error());


////////////////BLAH

}
else
die('submit something');