(function($){
    $.fn.alphanumeric = function(p) { 
        p = $.extend({
            ichars: "!@#$%^&*()+=[]\\\';,/{}|\":<>?~`.- ",
            nchars: "",
            allow: ""
        }, p);	
        return this.each( function() {
            if (p.nocaps) p.nchars += "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
            if (p.allcaps) p.nchars += "abcdefghijklmnopqrstuvwxyz";
            s = p.allow.split('');
            for ( i=0;i<s.length;i++) if (p.ichars.indexOf(s[i]) != -1) s[i] = "\\" + s[i];
                p.allow = s.join('|');
            var reg = new RegExp(p.allow,'gi');
            var ch = p.ichars + p.nchars;
            ch = ch.replace(reg,'');
            $(this).keypress ( function (e) {
                if (!e.charCode) k = String.fromCharCode(e.which);
                else k = String.fromCharCode(e.charCode);
                if (ch.indexOf(k) != -1) e.preventDefault();
                if (e.ctrlKey&&k=='v') e.preventDefault();
            });
            $(this).bind('contextmenu',function () {return false});
            $(this).bind('paste', function(e){return false});					
        });
    };
    
    $.fn.numeric = function(p) {
        var az = "abcdefghijklmnopqrstuvwxyz";
        az += az.toUpperCase();
        p = $.extend({
            nchars: az
        }, p);	
        return this.each(function() {
            $(this).alphanumeric(p);
        });
    };
    
    $.fn.alpha = function(p) {
        var nm = "1234567890";
        p = $.extend({
            nchars: nm
        }, p);	
        return this.each (function() {
            $(this).alphanumeric(p);
        });
    };
})(jQuery);