attivare campo di testo tramite checkbox

[brodik]

HTML:

<input type="checkbox" name="check" id="check" value="0" OnClick="javascript:active_input(this.id);" />
<input type="text" name="text" id="text" value="" disabled="disabled" />

JS:

function active_input(th) {
	if(document.getElementById(th).checked){
		document.getElementById('text').disabled=true;
	}else{
		document.getElementById('text').disabled=false;
	}
}