```Date: Nov 21, 2012 7:51 PM
Author: Dr Reinhard Simonovits
Subject: Cannot calculate with Dynamic variables

Hi,I have a problem with Dynamic variables.This is a prototype of a grading scheme. In reality it is bigger. The  10 pts  in initPtsPartAcome from the school.The output cell should be deployed as a CDF file for the teacher. The teacher enters the points of the students and gets a final mark.I have two questions.1) How can I limit the InputField to allow for integer numbers between 0 and 10?  If I enter anything else, say a negative number or a symbol,  it should be cleared automatically.2) In  "Why don't the calculations work?" you see expressions with Dynamic variables which I need to work with. What is wrong? What is the solution?DynamicModule[ {mark4 = 1/3,   mark3 = 0.51,   mark2 = 0.68,   mark1 = 0.80,   initPtsPartA = {     {10, 8, 10, 6},     {10, 5, 10, 5},     {10, 7, 10, 1}},   initPtsStudent, initPtsSchool, initPtsPartSum, numTable,   SchoolAPts, StudentAPts, StudentMinAchieved   },  numTable[x_, y_ /; OddQ[y]] := initPtsPartA[[x, y]];  numTable[x_, y_ /; EvenQ[y]] :=   InputField[Dynamic@initPtsPartA[[x, y]], Number,    ContinuousAction -> True, FieldSize -> 1];  initPtsPartSum[x_, y_, col_] :=   Dynamic@Total[initPtsPartA[[x ;; y, col]]];  SchoolAPts = (Total[initPtsPartA[[1 ;; 3, #]]] &) /@ {1, 3};  StudentAPts = (initPtsPartSum[1, 3, #] &) /@ {2, 4};  Column[{Grid[     Append[ Array[numTable, {3, 4}], (initPtsPartSum[1, 3, #] &) /@       Range[4]]],    {"Just Testing Values:", initPtsPartSum[1, 3, 1],     initPtsPartSum[1, 3, 2], initPtsPartSum[1, 3, 3],     initPtsPartSum[1, 3, 4], "Student Pts only:", StudentAPts},    {"Why don't the calculations work?",     Dynamic[5*initPtsPartSum[1, 3, 2] + 10],     Dynamic[initPtsPartSum[1, 3, 4] > 30],     Dynamic[ Total[(initPtsPartSum[1, 3, #] &) /@ Range[4]]  ],     Dynamic[(Total@StudentAPts)]/(Total@SchoolAPts)},    {"Why don't the calculations work?",     StudentMinAchieved =      Dynamic[(StudentAPts[[1]]/SchoolAPts[[1]] >          mark4) && (StudentAPts[[2]]/SchoolAPts[[2]] > mark4)]}    }]  ]Liebe Grüße, Best wishes, Reinhard-- *********************************************************              Dr. Reinhard SimonovitsHandelsakademie  |  Karl Franzens UniversityMath Department  |  Inst. for MathematicsGrazbachgasse 71 |  Heinrichstrasse 36               A-8010 Graz, AustriaEmail: Reinhard.Simonovits@uni-graz.at************************************************************
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