<input type="checkbox" name="var1" id="var1" value="One"> One
<input type="checkbox" name="var2" id="var2" value="Two"> Two
<input type="checkbox" name="var3" id="var3" value="Three"> Three
<input type="checkbox" name="var3" id="var4" value="Four"> Four

A perl-y or PHP-like example is as follows, use the language of your choice:

## In this example, incoming values are stored in %qs
## If a box is not CHECKED, it will not be in the incoming vars
## so simply check for it's existence. @list is the
## array/list of the checkboxes.

@list = ('var1','var2','var3','var4'); 
foreach $var (@list) { 
  if ($qs{$var}) { 
   ## you only need to "and" if $where has a value 
   if ($where) { $where .= ' and'; } 
   $where .= " field like '%$qs{$var}%'"; 
  } 
} 
$select = "select * from table"; 
if ($where) { $select .= " where ($where);"; } 

So if 1 and 3 are checked what you will have is

select * from table where (field like '%One%' and field like '%Three%');

Although it may be possible you are looking for OR, not AND. AND will only match on records meeting ALL conditions, or will match on ANY of the conditions.

Thanks, this makes sense, I'm using PHP, so some of the coding is different. I'm still trying to figure it out, but this is a good start.