function proveriFormu() {
				// txtbox class
				window.document.getElementById("SenderName").className="txtbox";
				window.document.getElementById("SenderEmail").className="txtbox";
				window.document.getElementById("SenderPhone").className="txtbox";
				// radio buttons
				window.document.getElementById("radioError").innerHTML="";
				
				
				var OK=true;
				
				// form validation
				
				// name validation
				if (window.document.getElementById("SenderName").value=="") 
					{
					window.document.getElementById("SenderName").className="txtbox_error";
					
					OK=false;
					}														
						
					
				// mail validation
				if (window.document.getElementById("SenderEmail").value=="")
					{
					window.document.getElementById("SenderEmail").className="txtbox_error";
					
					OK=false;
					}	
					
				// phone validation
				if (window.document.getElementById("SenderPhone").value=="")
					{
					window.document.getElementById("SenderPhone").className="txtbox_error";
					
					OK=false;
					}
	
					
				
	
				return OK;
	
			}