css - two div left right with auto width -

<div id="leftdiv" style="background: yellow; min-width: 400px; max-width: 800px;">left content left content left content</div>  <div id="rightdiv" style="background: red; width: 250px;">right content right content right content</div> 

i put float: left in left div max-width , min-width not working. how can fix ?

float right div must before left coz gives trouble in version of ie

<div id="rightdiv" >right content right content right content</div> <div id="leftdiv">left content left content left content</div> 

css same bot

#leftdiv {     background-color:yellow;     min-width:100%;     max-width:800px;     float:left; }  #rightdiv {     background-color:red;     width:250px;     float:right; }