html - Using css to keep elements centered -

I'm adding select dropdowns with jquery in a dynamic div I would like to start with the department and then once the center New dropdowns are added to exit

Here is CSS for divs:

  #pageMiddle {width: 940px; Margin: 0 auto; Align text: left; Status: Relative; } #searchbar {background: red; Width: 500px; Margin: 0 auto; } #searchwrapper {width: 850px; Background: blue; } #searchwrapper form {display: inline; Margin: 0 auto; }   
 and actual HTML:  
  & lt; Div id = "pageMiddle" & gt; & Lt; Div id = "holder" & gt; & Lt; Div id = "searchBar" & gt; & Lt; Div id = "searchwrapper" & gt; & Lt; Form name = "search_input" & gt; I have a & lt; Div id = "sBar1" style = "display: inline;" & Gt; & Lt; Select ID = "search_level" class = "selector search" name = "search_love" & gt; & Lt ;? Php echo "& lt; option & gt; level & lt; / option & gt;"; While ($ row = mysqli_fetch_array ($ result_level, MYSQLI_ASSOC)) {resonance "& lt; option value =". $ Line ['id']. "& Gt;" $ Line ['level'] "& Lt; / option & gt;"; ?} & Gt; & Lt; / Select & gt; & Lt; / Div & gt; & Lt; Div id = "sBar2" class = "select the searchbar" & gt; & Lt; / Div & gt; & Lt; Div id = "sBar3" class = "select the searchbar" & gt; & Lt; / Div & gt; In the tutor & lt; Input type = text class = "searchbox" id = "location" value = "location" /> & Lt; Input type = image src = "images / search_icon.png" class = "searchbox_submit" name = "searchbox_submit" onclick = "searchLocations ()" value = "" & gt; & Lt; / Form & gt; & Lt; / Div & gt; & Lt; / Div & gt; & Lt; / Div & gt; & Lt; / Div & gt;    
 
 
 I think you mean something like this?  
 The blue section is centered in the red section. This table was made with a display, which allows to focus indefinite size via automatic margin; Otherwise, this block element  and  must have fixed size.  
  #searchwrapper {display: table; Margin: 0 auto; }