function validateenquiry() {
    var error = true;
	var errorMsg = "";   
      
	var trimmed = document.getElementById("tbName").value.replace(/^\s+|\s+$/g, '') ;
    if (trimmed == "") {
        document.getElementById("tbName").focus();
        errorMsg="Please enter Name.\n";
        error=false;
    }
	var trimmed = document.getElementById("tbSurname").value.replace(/^\s+|\s+$/g, '') ;
    if (trimmed == "") {
        if(error==true){
          document.getElementById("tbSurname").focus();
        }
        errorMsg=errorMsg+"Please enter Surname.\n";
        error=false;
    }
	var trimmed = document.getElementById("tbPhone").value.replace(/^\s+|\s+$/g, '') ;
    if (trimmed == "") {
        if(error==true){
           document.getElementById("tbPhone").focus();
        }  
        errorMsg=errorMsg+"Please enter Telephone number.\n";
        error=false;
    }
    
	var str = document.getElementById("tbEmail").value; // email string
	var reg1 = /(@.*@)|(\.\.)|(@\.)|(\.@)|(^\.)/; // not valid
	var reg2 = /^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(\]?)$/; // valid
	if (!reg1.test(str) && reg2.test(str)) { // if syntax is valid
	} else {
        if(error==true) {
           document.getElementById("tbEmail").focus();
        }
	    errorMsg=errorMsg+"Incorrect email address.\n";
	    error= false;
	}	
	var trimmed = document.getElementById("tbCity").value.replace(/^\s+|\s+$/g, '') ;
    if (trimmed == "") {
        if(error==true){
           document.getElementById("tbCity").focus();
        }  
        errorMsg=errorMsg+"Please enter City.\n";
        error=false;
    }
  
	if (!document.getElementById("chkContactMe").checked && !document.getElementById("chkQuote").checked) {
	    if (error==true) document.getElementById("chkContactMe").focus();
	    document.getElementById("chkContactMe").style.backgroundColor = "yellow";
	    document.getElementById("chkQuote").style.backgroundColor = "yellow";
	    errorMsg+="Please select at least one of 'Please contact me' or 'Please quote me'.\n";
	    error=false;
	} else {
	    document.getElementById("chkContactMe").style.backgroundColor = "";
	    document.getElementById("chkQuote").style.backgroundColor = "";
	}
	
    if(!error) {
        alert(errorMsg);
        return error;
	} else {
	    disableSubmit();
        return error;
	}
}

function makeDivVisible() {
    var dv;
    dv = document.getElementById('divQuote');
    if (document.getElementById("chkQuote").checked) {
        dv.style.visibility = 'visible';
        dv.style.display = 'block';
    } else {
        dv.style.visibility = 'hidden';
        dv.style.display = 'none';
    }
}

function disableSubmit()
{
    document.getElementById('btnreset').disabled = true;
    var elem = document.getElementById('btnsubmit');
    var btn = document.createElement('input');
    btn.type = "button";
    btn.disabled = true;
    btn.value = "Submitting...";
    elem.parentNode.insertBefore(btn, elem);
    elem.style.display = 'none';
    elem.style.visibility = 'hidden';
}