Javscript to filter dots in a texbox

i want to filter dots in a textbox using javascript if the input contains only dots.
If the input contains dots in between alphabets and numerals the javascript should not filter.I have a javascript which filters dots even in between alphabets and numerals.
Can any1 Help me..Below is my script:

function addressValidation(obj)
{
var regex = new RegExp("[.]");
if(obj.value.match(regex))
{
alert("Dot is not allowed");
obj.focus();
return false;
}
}

 

If you want to catch only dots, use this:

var regex = new RegExp("^\\.+$");

Code (markup):