function addClass(element,value) {
  if (!element.className) {
    element.className = value;
  } else {
    newClassName = element.className;
    newClassName+= " ";
    newClassName+= value;
    element.className = newClassName;
  }
}


function validateForm(theInputs) {
	var missingFields = false;

	for (var i=0;i<theInputs.elements.length;i++) {
		var element = theInputs.elements[i];
			
			
			
			
			if(element.className.indexOf("alert") != -1 && isFilled(element) && element.className.indexOf("email") == -1) {
					//input style
					element.className = "required"
					//label style
					element.previousSibling.className = ""
			}
				
			if(element.className.indexOf("required") != -1) {
			
				if(!isFilled(element)){
					
					//input style
					element.className += " alert"
					//label style
					element.previousSibling.className = "alert"
					missingFields = true;
					
					
					element.onblur = function() {
						if(this.className.indexOf("alert") != -1 && isFilled(this)) {
					//input style
					this.className = "required"
					//label style
					this.previousSibling.className = ""
						}
					}
				}
				
				
			
			}
			
			
			if(element.className.indexOf("email") != -1) {
					if(!isEmail(element)){
					//input style
					element.className += " alert"
					//label style
					element.previousSibling.className = "alert"
					missingFields = true;
					
						element.onblur = function() {
							if(isEmail(this)) {
					//input style
								this.className = "email"
					//label style
								this.previousSibling.className = ""
							}
						}
					}

				}
			
		
	
	}	
	if (missingFields) { return false }
	else { return true}
	
}

function isFilled(field) {
	if(field.value.length < 1) {
		return false;
	}
	else {return true;}
	

}
function isEmail(field) {
  if (field.value.indexOf("@") == -1 || field.value.indexOf(".") == -1) {
    return false;
  } else {
    return true;
  }
}


function checkForm() {

	for(var i=0;i<document.forms.length;i++) {
		var thisForm = document.forms[i];
		
		thisForm.onsubmit = function() {
			if(!validateForm(this)) {
				alert("Red fields are required.");
				return false;
			}
		}
	}
}


function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}


addLoadEvent(checkForm);