How to unselect checkbox when everything deleted?

I'm trying to unselect the checkbox when all rows are deleted. This is my current code:

function removeElements() 
{
    var chxbox= this.form.getElementsByTagName('input');
    for (var i = chxbox.length; i--; ) {
        if (chxbox[i].name === 'delrow[]') {
            chxbox[i].checked = this.checked;
        }else (chxbox[i].name === 'delrow[]') {
            chxbox[i].checked = this.checked = false;
    }
}

This is my checkbox:

  <input type="checkbox"  onclick="removeElements.call(this);" />

The checked is okay,but the unchecked doens't seem to work.