<selecte name="list">
<option value="1">option</option>
...
</selecte>

<?php
//multi-list boxes post an array of results
//get this array into a single comma-seperated-value string
foreach($_POST['select'] as $key=>$val)
{
	//add item as comma-seperated-value
	$csv .= $val .',';
}
 
//trim trailing comma
$csv = rtrim($csv,',');
 
//INSERT $csv INTO A SINGLE FIELD IN YOUR DATABASE ROW HERE!!!
//you can do the sql HERE...
 
//end part one!
 
//later you can sort your comma-seperated-value that you retrieve from the database back into individual elements like so...
 
//you can do the sql HERE...
 
//store all individual items in an array
$arrayOfItems = explode(',',$csv);
 
//build each of your items in a list
foreach($arrayOfItems as $key=>$val)
{
	$output .= '<li>' . $val . '</li>';	
}
 
//display output
echo $output;
 
 
?>

<input type="checkbox" name="name1" /> sentence 1<br />
<input type="checkbox" name="name2" /> sentence 2<br />
<input type="checkbox" name="name3" checked="checked"/> sentence 3<br />
<input type="checkbox" name="name4" /> sentence 4

//array to hold checkbox options
$checkBoxOptions = array('sentence 1' , 'sentence 2' , 'sentence 3' , 'sentence 4');
 
//create checkbox output
$cbOut = '';
 
foreach($checkBoxOptions as $val)
{
	//test to see if stored choices match a checkbox value.
	if(in_array($val , $arrayOfItems))
	{
		//stored choice was found, mark this box
		$cbOut .= '<input type="checkbox" name="'.$val.'" checked="checked" value="'.$val.'"/><label>' . $val . '</label><br/>';		
	}
	else
	{
		//choice has not been stored, leave box unchecked
		$cbOut .= '<input type="checkbox" name="'.$val.'" value="'.$val.'"/><label>' . $val . '</label><br/>';
	}
}
 
//output checkboxes
echo $cbOut;