css - Align image to bottom of responsive container -

i'm trying align images bottom of container. however, site responsive, when change window size image moves up/down container seems fixed a point on page.

is there way fix baseline of image baseline of container indefinitely? essentially, image aligned bottom begin with, window contacts, text forces container expand , end white space below image.

my css image div follows:

.floatbottom {  height: 100%; position: absolute; bottom:0; width: 500px;  } 

css parent container:

#box{   height: auto; padding-top: 90px; padding-bottom: 90px; position: relative;  } 

html image in container:

<div id="box">     <div class="floatbottom">         <img src="/images/bottom.png">     </div> </div> 

any ideas massively appreciated!

 <div class="container">      <div class="content"></div>      <div class="floatbottom"></div>  </div> 

and set css content, height auto; , container height auto