All in one Validation in JavaScript

<script type="text/javascript">

        function Validation(obj1, req, email, Numeric) {

            try {

                var val1 = document.getElementById(obj1).value

                if (req == 1) { // For Required field Validation                   

                    if (val1.trim() == '') {

                        alert("Please enter valid value"); return false

                    }

                    return true;

                }

                if (email == 1) {   // For Email ID Validation

                    var filter1 = /^.+@.+\..{2,3}$/;

                    if (filter1.test(val1) != true) {

                        alert("Email ID is not valid");

                        return false;

                    }

                }

                if (Numeric == 1) {  // for Numeric Only Validation

                    var reg = /^-{0,1}\d*\.{0,1}\d+$/;

                    if (reg.test(val1) != true) {

                        alert("Please enter numeric only");

                        return false

                    }

                }

            }

            catch (e) {

            }

        }    

    </script>

In HTML:

<input type="submit" name="btn" value="Button" onclick="return Validation('txt',1,0,1);" 
          id="Submit" />