Add validation on multiple single checkbox

I have group of single checkbox for topic of the event. I want the checkbox to be required. The code will be used in Eloqua so HTML code can't be change, as well the onsubmit function.

<div id="formElement1"><input name="singleCheckbox" type="checkbox" value="on" disabled="disabled"><label style="margin-left: 4px">Topic 1</label></div>
<div id="formElement2"><input name="singleCheckbox2" type="checkbox" value="on" disabled="disabled"><label style="margin-left: 4px">Topic 2</label></div>
<div id="formElement3"><input name="singleCheckbox3" type="checkbox" value="on" disabled="disabled"><label style="margin-left: 4px">Topic 3</label></div>
<div id="formElement4"><input name="singleCheckbox4" type="checkbox" value="on" disabled="disabled"><label style="margin-left: 4px">Topic 4</label></div>
<div id="formElement5"><input name="singleCheckbox5" type="checkbox" value="on" disabled="disabled"><label style="margin-left: 4px">Topic 5</label></div>