function ProveriUnose(){
	//alert("ok");
	var Ok=true;
	
	// custom variables
	var name = window.document.getElementById('txtIme');
		var nameError = window.document.getElementById('nameError');
	var firmName = window.document.getElementById('txtNazivFirme');
	var mail = window.document.getElementById('txtEmail');
		var mailError = window.document.getElementById('mailError');		
	var captcha = window.document.getElementById('number');
	var idea = window.document.getElementById('txtMojaZamisao');
		var ideaError = window.document.getElementById('messageError');
	var grForm = window.document.getElementById('grForm');
	
	// defalut styles
	name.className = "textbox";
		nameError.innerHTML = "";
	firmName.className = "textbox";
	mail.className = "textbox";
		mail.innerHTML = "";
	idea.className = "textarea";
		ideaError.innerHTML = "";
	grForm.style.display = "none";
	
	// validate empty fields
	var required = [idea, name, mail, captcha];	
	for (i=0;i<required.length;i++) {
		if (required[i].value == "" || (required[i].value.length==0)){
			required[i].className = "textbox_error";
			Ok = false;
		}
	}
	
	// textarea check
	if(idea.value == ""  || (idea.value.length==0)){
		idea.className='textarea_error';
		ideaError.innerHTML = "Upišite opis projekta.";
		Ok=false;
	}
	
	// name check
	if(name.value === "" || (name.value.length==0)){
		name.className='textbox_error';
		nameError.innerHTML = "Ime je obavezno polje.";
		Ok=false;
	}
	
	// captcha check
	if(captcha.value === ""){
		captcha.className = "textbox_error";
		Ok = false;
	}
	
	// mail pattern
	var mailFileter = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
	if (!mailFileter.test(mail.value)){			
		mail.className = "textbox_error";
		mailError.innerHTML = "Upišite validnu email adresu!";
		Ok = false;
		}
	
	// main error message
	if(!Ok){
		grForm.style.display='';
		}
		
return Ok;
}