function elementById(x) {
if (document.getElementById) return document.getElementById(x);
	else if (document.all) return document.all[x];
	else if (document.layers) return document.layers[x];
	else return null;
}
				
function hide(shID) {
	elementById(shID).style.display = 'none';
}
		
function show(shID) {
	elementById(shID).style.display = 'block';
}
		
function choose() {
	for (var i = 0; i < document.get_free_player.player_external.length; i++) {
		if (document.get_free_player.player_external[i].selected) {
			var selectedVal = document.get_free_player.player_external[i].value;
		
			if(selectedVal == "custom"){
				show('video_source_enter'); 
				document.get_free_player.player_source.value = "enter a video url";
			}else if(selectedVal == "youtube"){
				show('video_source_enter'); 
				document.get_free_player.player_source.value = "enter a youtube video id";
			}else if(selectedVal == "vimeo"){
				show('video_source_enter'); 
				document.get_free_player.player_source.value = "enter a vimeo video id";
			}else{
				hide('video_source_enter'); 
			}
		}
	}
}