function GeoCalc(){
var Surface;
base = eval(document.triangle.base.value);
height = eval(document.triangle.height.value);

if((base > 0) && (height > 0)){
	Surface = FormatNumber((base * height)/2);
	
	if(Surface >= 100)
		resultSurface = "&#928; = 3.141592653589793<br />Surface<br />" + Surface + "  cm<sup>2</sup><br />" + FormatNumber(Surface/10000) + "  m<sup>2</sup><br />";
	else
		resultSurface = "&#928; = 3.141592653589793<br />Surface<br />" + Surface + "  cm<sup>2</sup><br />";
	
	document.getElementById("surface").innerHTML = resultSurface;
}

}