Clean inputs on focus, and refill on blur

gistfile1.js

<script type="text/javascript">
        jQuery.fn.doCleanInputs = function () {

            jQuery(this).each(function() {
            var default_value = this.value;
            jQuery(this).focus(function(){
                if(this.value == default_value) {this.value = '';}
            });
            jQuery(this).blur(function(){
                if(this.value == '') {this.value = default_value;}
            });
        });
        };
    </script>
    
  Usage:
  jQuery('.cleaninputs').doCleanInputs();