Simple implementation of javascript hashtable

function HashTable()
{
var size = 0;
var entry = new Object();
= function (key , value)
{
if(!(key))
{
size ++ ;
}
entry[key] = value;
}
= function (key)
{
return (key) ? entry[key] : null;
}
= function ( key )
{
if( (key) && ( delete entry[key] ) )
{
size --;
}
}
= function ( key )
{
return (key in entry);
}
= function ( value )
{
for(var prop in entry)
{
if(entry[prop] == value)
{
return true;
}
}
return false;
}
= function ()
{
var values = new Array();
for(var prop in entry)
{
(entry[prop]);
}
return values;
}
= function ()
{
var keys = new Array();
for(var prop in entry)
{
(prop);
}
return keys;
}
= function ()
{
return size;
}
= function ()
{
size = 0;
entry = new Object();
}
}