var DDSPEED = 5;
var DDTIMER = 15;

function checkfrm(obj) { 
	
	correct=true;

	inputs = obj.getElementsByTagName("input");
	textareas = obj.getElementsByTagName("textarea");
	
	fields = [inputs, textareas];
	for (var i in fields){
		for (var j in fields[i]){
			var ch = fields[i][j];
			if(ch.className&&ch.className.toLowerCase()=="necessary"&&ch.value==""){
			alert( "Заполните, пожалуйста, все поля, помеченные *" );
			return;
			}
			
			if(ch.name && ch.name.toLowerCase()=="email" && !checkEmail(ch.value)){
				alert("Введите, пожалуйста, правильный адрес электронной почты!");
				return;
			}
		}
	}
	document.form.submit();
}

function checkEmail(str){
	var template = /^(?:[a-zA-Z0-9_'^&/+-])+(?:\.(?:[a-zA-Z0-9_'^&/+-])+)*@(?:(?:\[?(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))\.){3}(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\]?)|(?:[a-zA-Z0-9-]+\.)+(?:[a-zA-Z]){2,}\.?)$/;
    str_trim = str.replace(/^\s*(.+?)\s*$/, "$1");
    if (template.test(str_trim)) {
		return true;
    }
    return false; 
}


// main function to handle the mouse events //
function ddMenu(parentId,childId,d){
  var h = document.getElementById(parentId);
  var c = document.getElementById(childId);
  clearInterval(c.timer);
  if(d == 1){
    clearTimeout(h.timer);
    if(c.maxh && c.maxh <= c.offsetHeight){return}
    else if(!c.maxh){
      c.style.display = 'block';
      c.style.height = 'auto';
      c.maxh = c.offsetHeight;
      c.style.height = '0px';
    }
    c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
  }else{
    h.timer = setTimeout(function(){ddCollapse(c)},50);
  }
}

// collapse the menu //
function ddCollapse(c){
  c.timer = setInterval(function(){ddSlide(c,-1)},DDTIMER);
}

// cancel the collapse if a user rolls over the dropdown //
function cancelHide(parentId, childId){
  var h = document.getElementById(parentId);
  var c = document.getElementById(childId);
  clearTimeout(h.timer);
  clearInterval(c.timer);
  if(c.offsetHeight < c.maxh){
    c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
  }
}

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(c,d){
  var currh = c.offsetHeight;
  var dist;
  if(d == 1){
    dist = (Math.round((c.maxh - currh) / DDSPEED));
  }else{
    dist = (Math.round(currh / DDSPEED));
  }
  if(dist <= 1 && d == 1){
    dist = 1;
  }
  c.style.height = currh + (dist * d) + 'px';
  c.style.opacity = currh / c.maxh;
  c.style.filter = 'alpha(opacity=' + (currh * 100 / c.maxh) + ')';
  if((currh < 5 && d != 1) || (currh > (c.maxh - 2) && d == 1)){
    clearInterval(c.timer);
  }
}