rem: this.checked = !this.checked; 
add: var clickedRadioButton = ((this.type == "radio") && (this.checked)); if (!clickedRadioButton) { this.checked = !this.checked; } 
context:     onLabelClick: function(e) {        this.checked = !this.checked;    },
meta: 8310	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8310/b2ab65df12d963bbce1c2bd2d14b84ac30fa1b93/LayerSwitcher.js/clean/lib/OpenLayers/Control/LayerSwitcher.js