SCRIPT438: Object doesn't support this property or method

Problem :

When trying to click on a check box I was getting this error message

SCRIPT438: Object doesn't support this property or method

Reason : 

The reason was that the Id of my inbox and the function it was calling on click was the same

<INPUT type="checkbox" id="isGeneral" onclick="isGeneral(this)" />

Solution :

Changed the function name like

<INPUT type="checkbox" id="isGeneral" onclick="isGeneralBestPractice(this)" />


And it was working fine after that.