I don’t know what is wrong with these html tags:W3C validator insists the button is not accepted:
<div id='mainDiv'>
<div id='div1' >
<form id='SampleFormID' action=''>
<input type='button' id='downloadSample' ><br>
</form>
</div>
</div>
W3C error:
Line 144, Column 49: document type does not allow element "INPUT" here;
missing one of "P", "H1", "H2", "H3", "H4", "H5", "H6", "PRE", "DIV",
"ADDRESS" start-tag
I'm using <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">.
You have to put the input-element inside a div for example.