function cilindervolume(){
	dcyl = document.SILO.doorsnee.value*10;
	hcyl = document.SILO.cylinderheight.value*10;
	radius2 = eval(dcyl*dcyl);
	cyl_opp = eval(Math.PI*Math.pow(dcyl,2)/4);
	cyl_inh = eval(hcyl*cyl_opp);
	cyl_vol = eval(cyl_inh*0.001);
	cyl_gal = eval(cyl_inh/3.78541178);
	cyl_ft3 = eval(cyl_vol/0.0283168466);
	document.SILO.inhoud.value=cyl_inh;
	document.SILO.volume.value=cyl_vol;
	document.SILO.us_gal.value=cyl_gal;
	document.SILO.us_ft3.value=cyl_ft3;
}