Google maps (Geocoding) problem

Hi all. I have run into a problem. I have embedded google maps into my web page using following source code: 

<iframe
class="style77" frameborder="0" marginheight="0" marginwidth="0" scrolling="no"
 src="https://www.google.co.za/maps?     t=m&amp;dg=opt&amp;ie=UTF8&amp;ll=-33.916013,18.654785&amp;spn=0.809147,0.826721&amp;z=9&amp;output=embed"
  width="300"></iframe>

Here is the picture of the embedded Google Maps, displayed in a frame: 

http://img837.imageshack.us/img837/4290/3a2l.png

There are 3 textboxs: street, suburb and town.

After the user has entered these 3 fields, a "View" button is clicked to display the map, which should display the new location in the frame containing embedded google maps

Thats where Im stuck. How can I pass the textboxes input into google maps so that it displays the specific location in this frame? I know that you need to manipulate string into string format: street + "," + suburb + "," + town;

Thanks