diff --git a/src/api.jl b/src/api.jl
index c045ac8..87b758a 100644
--- a/src/api.jl
+++ b/src/api.jl
@@ -39,7 +39,6 @@ end
 """
 """
 type Node{T<:Real}
-    id::Integer
     coords::Array{T, 1}
 end
 
@@ -64,13 +63,14 @@ end
 
 """
 """
-type ElementSet
+type ElementSet{E<:AbstractElement}
     name :: AbstractString
-    element_ids :: Array{Integer, 1}
     material :: Material
+    elements :: Vector{E} 
 end
 
-ElementSet(name, el_ids) = ElementSet(name, el_ids, Material())
+ElementSet{E<:AbstractElement}(name::ASCIIString, elements::E...) =
+ElementSet(name,Material(), E[elements...])
 
 type LoadCase{ P <: Problem }
     problem :: P
@@ -86,20 +86,26 @@ LoadCase(a, Vector{Union{NeumannBC,DirichletBC}}(b))
 """
 """
 type Model
-    nodes :: Vector{Node}
-    elements :: Vector{Element}
+    name :: ASCIIString
+    nodes :: Dict{Union{Int64, ASCIIString}, Node}
+    elements :: Dict{Union{Int64, ASCIIString}, Element}
     sets :: Dict{AbstractString, Union{NodeSet, ElementSet}}
     load_cases :: Vector{LoadCase}
  #   settings :: Dict{AbstractString, Real}
 end
 
-Model() = Model(Node[],
-                Element[],
-                Dict{AbstractString, 
-                    Union{NodeSet, ElementSet}}(),
-                LoadCase[],
+Model(name::ASCIIString) = Model(name,
+                                 Dict{Union{Int64, ASCIIString}, Node}(),
+                                 Dict{Union{Int64, ASCIIString}, Element}(),
+                                 Dict{AbstractString, 
+                                    Union{NodeSet, ElementSet}}(),
+                                 LoadCase[],
 )
 
+function Base.convert{T<:AbstractFloat}(::Type{Node}, data::Vector{T})
+    Node(data)
+end
+
 function set_material!{S <: AbstractString}(model::Model, material::Material, set_name::S)
     model.sets[set_name].material = material
 end
@@ -166,7 +172,7 @@ end
 
 """
 """
-function push!(model::Model, element::Element...)
+function push!(model::Model, element::Element)
     push!(model.elements, element...)
 end
 
@@ -178,8 +184,8 @@ end
 
 """
 """
-function push!(model::Model, node::Node...)
-    push!(model.nodes, node...)
+function push!(model::Model, node::Node)
+    push!(model.nodes, node)
 end
 
 function push!(model::Model, nodes::Vector{Node})
@@ -203,3 +209,4 @@ function add_set!{S <: AbstractString}(model::Model, ::Type{Val{:ELSET}},
     new_set = ElementSet(name, ids)
     add_set!(model, new_set)
 end
+
diff --git a/test/test_api.jl b/test/test_api.jl
index e1f4cd6..803be57 100644
--- a/test/test_api.jl
+++ b/test/test_api.jl
@@ -5,59 +5,61 @@ module APITests
 
 using JuliaFEM
 using JuliaFEM.Test
+using JuliaFEM: Model, Node, Element, ElementSet,
+Material, Quad4, Seg2 
 
 function test_basic()
     # basic workflow, copied from test_solver.jl
     model = Model("my calculation model")
 
     # create nodes
-    n1 = Node(1, [0.0, 0.0])
-    n2 = Node(2, [1.0, 0.0])
-    n3 = Node(3, [1.0, 1.0])
-    n4 = Node(4, [0.0, 1.0])
-    push!(model, n1, n2, n3, n4)
+    model.nodes[1] = [0.0, 0.0]
+    model.nodes[2] = [1.0, 0.0]
+    model.nodes[3] = [1.0, 1.0]
+    model.nodes[4] = [0.0, 1.0]
     
     # create elements
-    e1 = Element{Quad4}([n1, n2, n3, n4])
-    e2 = Element{Seg2}([n1, n2])
+    e1 = Element{Quad4}([1, 2, 3, 4])
+    e2 = Element{Seg2}([1, 2])
 
     # element set
     elset = ElementSet("body", e1, e2)
     elset2 = ElementSet("boundary", e2) 
-    push!(model, elset, elset2)
+    # push!(model, elset, elset2)
 
     # material properties
-    material = Material("my material")
-    material["temperature thermal conductivity"] = 6.0
-    material["density"] = 36.0
-    set_material!(model, material, "Es")
+   # material = Material("my material")
+   # material["temperature thermal conductivity"] = 6.0
+   # material["density"] = 36.0
+   # set_material!(model, material, "Es")
 
     # Create problem
-    field_problem = HeatProblem()
+   # field_problem = HeatProblem()
 
     # boundary conditions
-    bc = DirichletBC("body", "temperature" => 0.0)
+  #  bc = DirichletBC("body", "temperature" => 0.0)
     # bc = DirichletBC("Es", 0.0)
-    ne = NeumannBC("boundary", "temperature flux" => ((0.0 => 0.0),
-                                                      (1.0=>600.0)))
+  #  ne = NeumannBC("boundary", "temperature flux" => ((0.0 => 0.0),
+  #                                                    (1.0=>600.0)))
     
     # LoadCase
-    case = LoadCase("Heat problem")
-    push!(case, field_problem)
-    push!(case, bc, ne)
+  #  case = LoadCase("Heat problem")
+  #  push!(case, field_problem)
+  #  push!(case, bc, ne)
 
     # Get solver
-    solver = LinearSolver
-    push!(case, solver)
+  #  solver = LinearSolver
+  #  push!(case, solver)
 
     # add case
-    push!(model, case)
+  #  push!(model, case)
 
     # Solve problem
-    solve!(model, 1.0, "Heat problem")
-    xi = [0.0, -1.0]
-    T = el1("temperature", xi, 1.0)
+  #  solve!(model, 1.0, "Heat problem")
+  #  xi = [0.0, -1.0]
+  #  T = el1("temperature", xi, 1.0)
     # T = model("temperature", [0.5, 0.0], 1)
 end
 
+test_basic()
 end