function verzenden(){var goed=0;if(document.quiz.vraag[0].checked!=false){goed++}if(document.quiz.vraag[1].checked!=false){goed++}if(document.quiz.vraag[2].checked!=false){goed++}if(document.quiz.vraag[3].checked!=false){goed++}if(goed>0){return true}else{return false}}function changeLayerVisibility(layerID,layerState){if(document.layers){document.layers[layerID].display=layerState?layerState:(document.layers[layerID].display=="block"?"none":"block")}else if(document.getElementById){var obj=document.getElementById(layerID);obj.style.display=layerState?layerState:(obj.style.display=="block"?"none":"block")}else if(document.all){document.all[layerID].style.display=layerState?layerState:(document.all[layerID].style.display=="block"?"none":"block")}}