/**
*  ensure specified input fields will accept those predefined values
*  two configurable options
*  1. allow: only those specified within this option will be acceptable 
*  2. disallow: anything (or only those specified within allow option if allow option isn't empty)
*               will be acceptable except those specified within this option 
*/
jQuery.fn.inputValue = function(options) {
    var settings = jQuery.extend({ allow: '', disallow: '' }, options);
    return jQuery(this).keypress
		(

			function(e) {

			    if (!e.charCode)
			        var code = String.fromCharCode(e.which);
			    else
			        var code = String.fromCharCode(e.charCode);
			    if (code && (typeof (e.keyCode) == 'undefined' || (e.keyCode != 8 && e.keyCode != 46))) {
			        if (settings.allow.length != 0 && settings.disallow.length != 0) {
			            if (settings.allow.indexOf(code) == -1) {
			                e.preventDefault();
			            } else if (settings.disallow.indexOf(code) != -1) {
			                e.preventDefault();
			            }
			        } else if (settings.allow.length != 0) {
			            if (settings.allow.indexOf(code) == -1) {
			                e.preventDefault();
			            }
			        } else if (settings.disallow.length != 0) {
			            if (settings.disallow.indexOf(code) != -1) {
			                e.preventDefault();
			            }
			        }
			    }
			    if (e.ctrlKey && code == 'v')
			        e.preventDefault();
			    $(this).bind('contextmenu', function() { return false });


			}
		);

};
/**
*	input fields will accept valid email address
*/
jQuery.fn.inputEmail = function()
{
		return this.each (function()
			{
				jQuery(this).inputValue({allow:'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@.0123456789'});
			}
		);		
};
/**
*	input fields will accept digits only
*/
jQuery.fn.inputInteger = function()
{
		return this.each (function()
			{
				jQuery(this).inputValue({allow:'9876543210'});
			}
		);	
};
/**
*	input fields will accept digits and dots.
*/
jQuery.fn.inputFloat = function()
{
		return this.each (function()
			{
			jQuery(this).keypress(function(e) {
			if (!e.charCode)
			        var code = String.fromCharCode(e.which);
			    else
			        var code = String.fromCharCode(e.charCode);
					if (code == '.') alert('Пожалуйста, используйте запятую (,) как десятичный разделитель.');
			});
				jQuery(this).inputValue({allow:'0123456789,'});
			}
		);		
};
/**
*	input fields will accept all letters (case insensitive)
*/
jQuery.fn.inputLetter = function()
{
		return this.each (function()
			{
				jQuery(this).inputValue({allow:'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'});
			}
		);		
};