checkbox search by php [closed]

I have several checkboxes by php. I want to search the database and display the selected conditions when I select the first and second checkboxes. When I select one checkbox, I have no problem, but when I select two checkboxes, the conditions are not displayed.

enter code here

<form name="f1" action="">
  <label>ALL</label>
  <input type="checkbox" name="ch[]" id="ch1" value="all">
  <label>GIRL</label>
  <input type="checkbox" name="ch[]" id="ch2" value="girl">
  <label>BOY</label>
  <input type="checkbox" name="ch[]" id="ch3" value="boy">
  <label>NONE</label>
  <input type="checkbox" name="ch[]" id="ch3" value="none">
  <input type="submit" name="sub1" value="search"
</form>