function explode( delimiter, string, limit ) {
	// http://kevin.vanzonneveld.net
	// +     original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// +     improved by: kenneth
	// +     improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// +     improved by: d3x
	// +     bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// *     example 1: explode(' ', 'Kevin van Zonneveld');
	// *     returns 1: {0: 'Kevin', 1: 'van', 2: 'Zonneveld'}
	// *     example 2: explode('=', 'a=bc=d', 2);
	// *     returns 2: ['a', 'bc=d']

	var emptyArray = { 0: '' };

	// third argument is not required
	if ( arguments.length < 2 ||
		typeof arguments[0] == 'undefined' ||
		typeof arguments[1] == 'undefined' )
	{
		return null;
	}

	if ( delimiter === '' ||
		delimiter === false ||
		delimiter === null )
	{
		return false;
	}

	if ( typeof delimiter == 'function' ||
		typeof delimiter == 'object' ||
		typeof string == 'function' ||
		typeof string == 'object' )
	{
		return emptyArray;
	}

	if ( delimiter === true ) {
		delimiter = '1';
	}

	if (!limit) {
		return string.toString().split(delimiter.toString());
	} else {
		// support for limit argument
		var splitted = string.toString().split(delimiter.toString());
		var partA = splitted.splice(0, limit - 1);
		var partB = splitted.join(delimiter.toString());
		partA.push(partB);
		return partA;
	}
}


function isset(  ) {
	// http://kevin.vanzonneveld.net
	// +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// +   improved by: FremyCompany
	// +   improved by: Onno Marsman
	// *     example 1: isset( undefined, true);
	// *     returns 1: false
	// *     example 2: isset( 'Kevin van Zonneveld' );
	// *     returns 2: true

	var a=arguments, l=a.length, i=0;

	if (l===0) {
		throw new Error('Empty isset'); 
	}

	while (i!==l) {
		if (typeof(a[i])=='undefined' || a[i]===null) { 
			return false; 
		} else { 
			i++; 
		}
	}
	return true;
}


function array_key_exists ( key, search ) {
	// http://kevin.vanzonneveld.net
	// +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// +   improved by: Felix Geisendoerfer (http://www.debuggable.com/felix)
	// *     example 1: array_key_exists('kevin', {'kevin': 'van Zonneveld'});
	// *     returns 1: true

	// input sanitation
	if( !search || (search.constructor !== Array && search.constructor !== Object) ){
		return false;
	}

	return key in search;
}

function is_int( mixed_var ) {
	// http://kevin.vanzonneveld.net
	// +   original by: Alex
	// +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// +    revised by: Matt Bradley
	// +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// %        note 1: 1.0 is simplified to 1 before it can be accessed by the function, this makes
	// %        note 1: it different from the PHP implementation. We can't fix this unfortunately.
	// *     example 1: is_int(23)
	// *     returns 1: true
	// *     example 2: is_int('23')
	// *     returns 2: true
	// *     example 3: is_int(23.5)
	// *     returns 3: false
	// *     example 4: is_int(true)
	// *     returns 4: false
	
	if (mixed_var.match(/^[0-9]+$/))
		return true;
	
	if (typeof mixed_var !== 'number') {
		return false;
	}

	if (parseFloat(mixed_var) != parseInt(mixed_var, 10)) {
		return false;
	}
	
	return true;
}