function NumOnly(e) {
var KeyCode = (e.keyCode) ? e.keyCode : e.which;
return ((KeyCode == 8) // backspace
|| (KeyCode == 9) // tab
|| (KeyCode == 37) // left arrow
|| (KeyCode == 39) // right arrow
|| (KeyCode == 46) // delete
|| (KeyCode == 45)
|| ((KeyCode > 47) && (KeyCode < 58)) // 0 - 9
);
}

function chkForm(F) {
   if(F.name.value=='')
 	{alert("Please Enter name");
	document.f1.name.focus();

	 return false;
	}
	if(F.telephone.value=='')
	{
	alert("Enter Phone no");
	document.f1.telephone.focus();
	return false;
	}
	
	if(F.email.value=='')
	{
	alert("Please Enter email address");
	document.f1.email.focus();
	return false;
	}
	if(F.verif_box.value=='')
	{
	alert("Please Enter verification code");
	document.f1.verif_box.focus();
	return false;
	}
	if (isValidEmail(F.email.value) && isValidPhoneNumber(F.telephone.value)) return true;
	else return false;
}
function isValidEmail(string) {
	if (!(string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)) {
		alert('Please give a valid email address. \n \'' + string + '\' - is in wrong format.');
		return false;
	} else return true;
}

function isValidPhoneNumber(s) {   

	// NULL CHECK
	if (s == '') {
		alert('Please enter the phone number.');
		return false;
	}

	// CHECK FOR VALID INTEGER.
	var i;
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) {
			alert('Please give a valid phone number.');
			return false;
		}
    }

	// MINIMUM OF SEVEN NUMBERS
	if (s.length < 7) {
		alert('Please enter minimum of 7 numbers for phone number.');
		return false;
	}

	return true;
}