Changing placemark balloons for hundreds of points - kml

Question

I have a KML file with individual placemarks for gas station locations in the the city. (I had created this in GeoMedia and exported to KML).
I would like to revise the balloon style of each of the placemarks to something similar to one of these balloon styles -
http://earth.google.com/outreach/tutorial_balloon.html
Is there any manner in which I can apply the balloon style to each placemark in the file? Would I have to do it point by point, or can I place the balloon style at the top of the file and have the other placemarks reference that style?
I am very new to KML so any insight would be appreciated.
Thanks
#Matt - I have used your suggestions and tried various iterations but just cant seem to get it right. The file already has the placemarks created - and I want to just edit the style which includes adding logo, remove the directions, and so on.
The new style appears, but the schema text is not appearing in the placemark balloon.
I have pasted some of the code below - any thoughts would be appreciated.
<Schema name="" id="Schema20">
<SimpleField type="xsd:int" name="Building_ID"></SimpleField>
<SimpleField type="xsd:string" name="Building Name"></SimpleField>
<SimpleField type="xsd:string" name="Street Address"></SimpleField>
<SimpleField type="xsd:string" name="Office Type"></SimpleField>
<SimpleField type="xsd:double" name="GFA (m2)"></SimpleField>
<SimpleField type="xsd:string" name="GFA_(sqft)"></SimpleField>
<SimpleField type="xsd:int" name="Storeys"></SimpleField>
<SimpleField type="xsd:int" name="Year Built/Occupied">
</SimpleField></Schema>
<Style id="TestStyle">
<BalloonStyle>
<bgColor>ffffffbb</bgColor>
<text><![CDATA[<b><font color="#CC0000" size="+3">$[name]</font></b><br/><br/>
<font face="Courier">$[description]</font><br/><br/> $[geDirections] ]]>
</text>
</BalloonStyle>
</Style>
<Folder>
<name>Office Buildings</name>
<Placemark>
<name>539</name>
<styleUrl>#TestStyle</styleUrl>
<ExtendedData>
<SchemaData schemaUrl="#Schema20">
<SimpleData name="Building_ID">111</SimpleData>
<SimpleData name="Building Name">Name</SimpleData>
<SimpleData name="Street Address">Address</SimpleData>
<SimpleData name="Office Type">Secondary Office</SimpleData>
<SimpleData name="GFA (m2)">100</SimpleData>
<SimpleData name="GFA_(sqft)">1000</SimpleData>
<SimpleData name="Storeys">5</SimpleData>
<SimpleData name="Year Built/Occupied">2010</SimpleData>
</SchemaData>
</ExtendedData><Point>
<coordinates>-122.370533,37.823842,0</coordinates></Point>
</Placemark>
..... 1000 more like this
#Matt -
What I am running into is that if I use in the balloon style, then the data from the Schema which I referenced in my earlier post does not appear in the balloon.
If I leave the blank then the Schema will appear in the balloon.
Do you know how I can have both appear?
Thanks,
<BalloonStyle>
<text>
<![CDATA[<img align="right" src="http://www.website.com/logo.jpg" width="175">]]>
$[description]
</text>
<bgColor>ffffffbb</bgColor>
</BalloonStyle>

Answer 1

you can use styleUrl for you placemarks (which you will need to apply to all of your placemarks that you want to have a selected style):
<styleUrl>#someIDforStyle</styleUrl>
if the style section is in a different file then just add in the link:
<styleUrl>styles\pathToFile\StyleFile.kml#someIDforStyle</styleUrl>
both above will link a certain Style with that ID similar to:
<Style id='someIDforStyle'>
<BalloonStyle>
<text>
<![CDATA[ ....
your are going to want to add html here to make your balloons similar to that link
...
]]>
</text>
</BalloonStyle>
</Style>
you might check this kml link out for adding Custom Data: https://developers.google.com/kml/documentation/extendeddata