function Hashtable()
	{
    		this.hashtable = new Array();
	
		this.clear = function( ) {
    			this.hashtable = new Array();
		}


		this.containsKey = function( key ) {
    			var exists = false;

    			for (var i in this.hashtable) {
        				if (i == key && this.hashtable[i] != null) {
           					exists = true;
            					break;
        				}
    			}
    			return exists;
		}


		this.containsValue = function( value ) {
    			var contains = false;
    			if (value != null) {
        				for (var i in this.hashtable) {
            					if (this.hashtable[i] == value) {
                						contains = true;
                						break;
            					}
        				}
    			}

    			return contains;
		}


		this.get  = function( key ){
    			return this.hashtable[key];
		}

		this.isEmpty = function( ){
    			return (parseInt(this.size()) == 0) ? true : false;
		}

		this.keys = function( ){
   			var keys = new Array();
    			for (var i in this.hashtable) {
       				if (this.hashtable[i] != null) 
            				keys.push(i);
    			}
    			return keys;
		}

		this.put =  function( key, value ){
    			if (key == null || value == null) {
        				throw "NullPointerException {" + key + "},{" + value + "}";
    			}else{
        				this.hashtable[key] = value;
   			 }
		}

		this.remove = function( key ){
    			var rtn = this.hashtable[key];
    			this.hashtable[key] = null;
    			return rtn;
		}

		this.size = function( ){
   			 var size = 0;
    			for (var i in this.hashtable) {
        				if (this.hashtable[i] != null) 
            					size ++;
    			}
    			return size;
		}

		this.toString = function( ){
    			var result = "";
    			for (var i in this.hashtable)
    			{      
       				if (this.hashtable[i] != null) 
				{
					if( typeof(this.hashtable[i]) == "string" )
            						result += ", \"" + i + "\":\"" + this.hashtable[i] + "\""; 
					else
						result += ", \"" + i + "\":" + this.hashtable[i]; 
				}
    			}
    			return result.substr( 1 );
		}

		this.values = function( ){
    			var values = new Array();
    			for (var i in this.hashtable) {
        				if (this.hashtable[i] != null) 
            					values.push(this.hashtable[i]);
    			}
    			return values;
		}

	}