HTML & CSS

I have been trying to import Google Maps into my website, and I'm using a site then automatically generates the code. It offers you the height and width you would like your map. I want my map to stretch and fill 100% of its container, but I dont know what to change to make that happen within this code: html <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script><div style="overflow:hidden;height:300px;width:600px;"><div id="gmap_canvas" style="height:300px;width:600px;"></div><style>#gmap_canvas img{max-width:none!important;background:none!important}</style><a class="google-map-code" href="http://goertz-gutschein-map.com" id="get-map-data">http://goertz-gutschein-map.com</a></div><script type="text/javascript"> function init_map(){var myOptions = {zoom:15,center:new google.maps.LatLng(-28.0172605,153.4256987),mapTypeId: google.maps.MapTypeId.ROADMAP};map = new google.maps.Map(document.getElementById("gmap_canvas"), myOptions);marker = new google.maps.Marker({map: map,position: new google.maps.LatLng(-28.0172605, 153.4256987)});infowindow = new google.maps.InfoWindow({content:"<b></b><br/><br/> Gold Coast" });google.maps.event.addListener(marker, "click", function(){infowindow.open(map,marker);});infowindow.open(map,marker);}google.maps.event.addDomListener(window, 'load', init_map);</script>