The html code needed for your button is shown below. Please read the comments contained within the code to understand how to customize the form for your use.

<form action="http://www.buttontel.com/callme/clicktocall.cfm" method="post">

<!--Either select from a list of country codes. (A full country code list is available here)-->
<select name="CODE">
   <option value="44" selected>UK (+44)  
   <option value="1">USA (+1)  
   <option value="213">Algeria (+213)  
   <option value="376">Andorra (+376)  
</select>
<!--Or, if all your customer will be from one country, hard code that country code as a hidden value-->
<!--input type="hidden" name="CODE" value="44">-->

<input type="text" name="TELEPHONE">
<input type="hidden" name="ALIAS" value="You can create an alias from your account">

<input type="hidden" name="CALLTYPE" value="[select from below]">
<!--A = calls agent first, no welcome message-->
<!--B = calls customer first, no welcome message-->
<!--C = Calls agent first, welcome message-->
<!--D = Calls customer first, welcome message-->

<!--In addition a number can be added after C or D-->
<!--nothing = Message to customer-->
<!--1 = Message to customer-->
<!--2 = Message to agent-->
<!--3 = Message to both-->

<!--Name, Email, Product, Company and Postcode are optional and there are 5 additional optional fields that can be set. You can use any html form element for these fields. e.g. a drop down list of products-->
<input type="text" name="NAME">
<input type="text" name="EMAIL">
<input type="text" name="PRODUCT">
<input type="text" name="COMPANY">
<input type="text" name="POSTCODE">

<input type="text" name="EXTRA1">
<input type="text" name="EXTRA2">
<input type="text" name="EXTRA3">
<input type="text" name="EXTRA4">
<input type="text" name="EXTRA5">


<!--enter the name of your server folder where the response pages will reside. See below for example response pages.-->
<input type="hidden" name="RESPONSEURL" value="http://www.buttontel.com/callme/">

<!--Allow a delay to be set if the customer is on dial-up, or use this field to allow the customer to specify when they want to be called-->
<select name="DELAY">
<option value="0">now  
<option value="1">1 minute  
<option value="5">5 minutes  
</select>

<!--use an image to trigger the call-->
<input type="image" name="DIAL" src="myimage.gif" border="0">


</form>

Response pages:
success.htm
failNumber.htm
failUnavailable.htm
failOutOfOffice.htm