[Rise]

<input type="button" id="pdfloader" value="Загрузить" />

<script>
window.onload = function() {
	var button = document.getElementById('pdfloader');
	document.body.onblur = function(){ button.disabled = false };
	button.onclick = function(){
		this.disabled = true;
		document.location = '/download/rar/99';
	};
}
</script>