function valid() {
    a = document.form;
    if (a.Name.value == "") {
        alert("Please enter your Name");
        a.Name.focus();
        a.Name.select();
        return false;
    }
    if (a.CompanyName.value == "") {
        alert("Please enter your Company Name");
        a.CompanyName.focus();
        a.CompanyName.select();
        return false;
    }
    if (a.TelephoneNo.value == "") {
        alert("Please enter your Contact Number");
        a.TelephoneNo.focus();
        a.TelephoneNo.select();
        return false;
    }
    if (a.email.value == "") {
        alert("Please enter your Email Address");
        a.email.focus();
        a.email.select();
        return false;
    } else {
        var emailfilter = /^\w+[\+\.\w-]*@([\w-]+\.)*\w+[\w-]*\.([a-z]{2,4}|\d+)$/i;
        var returnval = emailfilter.test(document.form.email.value);
		if(returnval == false) {
            alert("Please enter a valid Email Address.");
			document.form.email.select();
			return false;
        }
    }
    if (a.NatureOfEnquiry.value == "") {
        alert("Please enter your Message");
        a.NatureOfEnquiry.focus();
        a.NatureOfEnquiry.select();
        return false;
    }
    return;
}