MyMonTools/mymontools/static/js/checkbox.js

function checkboxes_CheckAll(elementName, state) {
	checkboxes = document.getElementsByName(elementName)

	for ( var i=0, n=checkboxes.length; i<n; i++ ) {
		if ( checkboxes[i].type == "checkbox" ) {
			checkboxes[i].checked = state;
		}
	}

}