function validate()
{

    document.getElementById('submit').disabled=true;
    var name=document.getElementById("name").value;
    var email=document.getElementById("email").value;
    var business_name=document.getElementById("business_name").value;
    var message=document.getElementById("enquiry").value;
    var listradio=document.getElementById('yes');
    var resellerradio=document.getElementById('na');
	var txtNumber=document.getElementById("txtNumber").value;
    var error = "";
    if(name == "") {
            error += 'Please fill in your Name.\n';
    }
    if(email == "") {
            error += 'Please fill in your Email address.\n';
    } else {
            if(!isValidEmail(email)) {
            error += 'The Email address is not a valid format.\n';
            }
    }
    if(!listradio.checked) {
	    if(message == "") {
	            error += 'Please write a Message.\n';
	    }
	} else {
		if((resellerradio.checked) && (business_name == "")) {
	            error += 'Please fill in your Business Name.\n';
		}
	}
    if(txtNumber == "") {
            error += 'Please enter the Verification Number.\n';
    }

    if(error == "") {
            return true;
    } else {
        	document.getElementById('submit').disabled=false;
            alert(error);
            return false;
    }

}

function isValidEmail(str) {

   return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);

}