Question

need to enable a button if the checkbox is enabled using javascript in aspx page. Here is my code in aspx page. Please Help !

<script type="text/javascript">
function checkButt(obj) {
    alert("Inside the function");
    document.getElementById('<%=btnLoadForm.ClientID%>').disabled = !obj.checked;
}

Answer 1

Instead of:

document.getElementById('<%=btnLoadForm.ClientID%>').disabled = !obj.checked;

You could try removing the disabled property from the element (add your logic as needed):

document.getElementById('<%=btnLoadForm.ClientID%>').removeAttribute("disabled")

Where disabled is a Boolean attribute, the value doesn’t make much of a difference. You can read more on this in a similar post: HTML – Why boolean attributes do not have boolean value?

UPDATE:

You would need logic around the removeAttribute statement. Something similar to:

function checkButt(obj) {
    if(obj.checked)
      document.getElementById('<%=btnLoadForm.ClientID%>').removeAttribute("disabled");
}

This would enable document.getElementById('<%=btnLoadForm.ClientID%>') if obj.checked is checked.