well after diving and testing here and there I found a way and successfully tested.
1> First and formost, the developer need to follow the procedures in this page:
http://developer.android.com/guide/google/gcm/gs.html
2> In the app side, you will send users devices information; but all that matters is only the "registration id" , so make sure you save this in the database coz you'll use it to loop through your database records when sending notifications.
3> Now the server side script in Coldfusion which is really easy:
<!---Place this above your html tag--->
<cfsetting requesttimeout="80000000000000">
<cfset appName = 'YourAppName'>
<cfset registrationArray = ArrayNew(1)>
<cfquery datasource="devicesDSN" name="rsCount">
SELECT COUNT(intGCMuserID) AS TotalRecords
FROM gcmusers_tbl
WHERE appName = <cfqueryparam cfsqltype="cf_sql_clob" value="#appName#">
</cfquery>
<!---Google is limited to send only to 1000 devices at a time so we need to nest the cfloop of the array inside another cfloop pertaining to our total recordCount from the recordset so we'll use the Ceiling to control the number of loops needed to make sure we sent to all the users if they exceed google limit--->
<cfset LoopingNo = Ceiling(rsCount.TotalRecords/1000)>
<cfset fromRec = 1>
<cfset toRec = 1000>
<!---Now place the following code inside the body tag of your cfm page--->
<cfif isDefined("FORM.pushButton")>
<cfquery datasource="devicesDSN" name="rs">
SELECT regID
FROM gcmusers_tbl
WHERE appName = <cfqueryparam cfsqltype="cf_sql_clob" value="#appName#">
ORDER BY intGCMuserID DESC
</cfquery>
<cfloop from="1" to="#loopingNo#" index="i">
<cfloop query="rs">
<cfset ArrayAppend(registrationArray, "#regID#")>
</cfloop>
<cfset stFields =
{ "data"= {
"title" = "#FORM.title#",
"message"= "#FORM.message#"
},
"registration_ids"= #registrationArray#
}
>
<cfhttp url="https://android.googleapis.com/gcm/send" method="post" result="httpResp" timeout="600">
<cfhttpparam type="header" name="Content-Type" value="application/json"/>
<cfhttpparam type="header" name="Authorization" value="key=yourAPIkeyFromGoogle">
<cfhttpparam type="body" value="#serializeJSON(stFields)#">
</cfhttp>
<cfset temp = ArrayClear(registrationArray)>
<cfset fromRec = fromRec + 1000>
<cfset toRec = toRec + 1000>
</cfloop>
<h2 align="center" style="color:red;">Sent to: <cfoutput>#rs.RecordCount#</cfoutput> Devices/Users </h2>
<h3 align="center"><a href="thispage.cfm">>>>again</a></h3>
<cfelse>
<cfform>
<table width="400" border="1" align="center" cellpadding="2" cellspacing="2">
<tr valign="top">
<th scope="row">Title:</th>
<td><label for="title"></label>
<cfinput type="text" name="title" required="yes" id="title" maxlength="30" width="300" message="Type Title"></td>
</tr>
<tr valign="top">
<th scope="row">Message:</th>
<td><label for="message"></label>
<cftextarea name="message" cols="45" rows="2" required="yes" id="message" maxlength="120" message="Type Message"></cftextarea></td>
</tr>
<tr>
<th scope="row"> </th>
<td><cfinput type="submit" name="pushButton" value="send" id="pushButton"></td>
</tr>
</table>
</cfform>
</cfif>
