function docalc(x) {
	var y=parseFloat(document.getElementById("a").value.replace(",","."));
	var z=parseFloat(document.getElementById("b").value.replace(",","."));
	if(!x) {
		if(!y||isNaN(y)) {
			y=0;
			document.getElementById("a").value=0;
		}
		if(y==90)
			document.getElementById("b").value="∞";
		else if(y==-90)
			document.getElementById("b").value="-∞";
		else if(Math.abs(y)>90)
			document.getElementById("b").value="";
		else
			document.getElementById("b").value=Math.round(Math.tan(y/180*Math.PI)*1000000)/10000;
	} else {
		if(!z||isNaN(z)) {
			z=0;
			document.getElementById("b").value=0;
		}
		document.getElementById("a").value=Math.round(Math.atan(z/100)*180/Math.PI*10000)/10000;
	}
}