function calculate() {
var selectSquare = document.getElementById('square').value*200;
var selectCorner = document.getElementById('corner').value*50;
var selectPipes = document.getElementById('pipes').value*150;
var selectPerimeter = document.getElementById('perimeter').value*50;
var selectElectrolier = document.getElementById('electrolier').value*100;
var selectSpotLight = document.getElementById('spot_light').value*200;
var selectMaterial = +document.querySelector('#material').value;
var raschet = selectSquare + selectCorner + selectPerimeter +
selectPipes + selectElectrolier + selectSpotLight + selectMaterial;
document.getElementById('summa').innerText = raschet +" р.";
return true;
}