I have simple insert code and form. However I want people to be able leave some fields blank if they want to. Yet inserted into the database is "No Details Submitted"

For example if someone does not want to submit a budget they can leave the cell blank but I want to echo something to say that "No Details Submitted"

I need something like this:

    if(!isset($_POST['budget']) || empty($_POST[budget'])) {
    INSERT INTO eventjobs  = "No Details Submitted."; 


Can anyone advise how I should do this please?

    $organiserid = $row['id'];
	$eventlocation = $row['town'];
	$eventcountry = $row['country'];
    $eventname = mysql_real_escape_string(trim($_POST['eventname']));
	$eventdetails = mysql_real_escape_string(trim($_POST['eventdetails']));
	$supplier1 = mysql_real_escape_string(trim($_POST['supplier1']));
	$budget1 = mysql_real_escape_string(trim($_POST['budget1']));
        $query = mysql_query("INSERT INTO eventjobs (dateregistered, eventname, eventdetails, organiserid, eventlocation, eventcountry, supplier1, budget1) VALUES (NOW(), '" .$eventname."','" .$eventdetails."',  '" .$organiserid."', '" .$eventlocation."',  '" .$eventcountry."',   '" .$supplier1."', '" .$budget1."' ) ");


	  		<div class="registerinputcelltop">
					<div class="datainput">
					<li class="li_1" >
			  <div class="registerinputleft">	
           Event Name (Optional):
			  <div class="registerinputright">
         <input class="field" type="text" name="eventname" type="text" width="600" value="" />