if (document.all) { document.styleSheets[0].addRule(".RightAlign","text-align: right"); document.styleSheets[0].addRule(".CalcTable","background-color: buttonface"); document.styleSheets[0].addRule(".CalcCaptionBack","background-color: activecaption"); document.styleSheets[0].addRule(".CalcCaptionText","color: captiontext"); document.erlangb.Lines_Edit.style.backgroundColor="buttonface" } BHT=1; blocking=2; lines=3; BHTValue=0; BlockingValue=0; LinesValue=0; unknownval=lines; ResultsOpen=false; HelpOpen=false; var ResultsArray=new MakeArray(80); ResultIndex=1; wrapped=false; function ChangeUnknown(NewUnknown) { with (document.erlangb) { unknownval=NewUnknown; if (NewUnknown==BHT) { BHT_Edit.value=""; if (document.all) { Blocking_Edit.style.backgroundColor="window"; Lines_Edit.style.backgroundColor="window"; BHT_Edit.style.backgroundColor="buttonface"; } } if (NewUnknown==blocking) { Blocking_Edit.value=""; if (document.all) { Blocking_Edit.style.backgroundColor="buttonface"; Lines_Edit.style.backgroundColor="window"; BHT_Edit.style.backgroundColor="window"; } } if (NewUnknown==lines) { Lines_Edit.value=""; if (document.all) { Blocking_Edit.style.backgroundColor="window"; Lines_Edit.style.backgroundColor="buttonface"; BHT_Edit.style.backgroundColor="window"; } } } } function ValidateLines() {var LinesValue; with (document.erlangb) {ClearUnknown(); if ((Lines_Edit.value!="") && (unknownval !=lines)) {LinesValue=LinesNumber() if (LinesValue==0) {Lines_Edit.value=""} else {if ((LinesValue<1) || (LinesValue>180)) {alert("Lines figure must be between 1 and 180"); Lines_Edit.value="";} else {Lines_Edit.value=LinesValue} }}}} function ValidateBHT() {var BHTValue; with (document.erlangb) {ClearUnknown(); if ((BHT_Edit.value!="") && (unknownval!=BHT)) {BHTValue=BHTNumber(); if (BHTValue==0) {BHT_Edit.value=""} else {BHTValue=Math.round(BHTValue*1000)/1000; if ((BHTValue<0.1) || (BHTValue>180)) {alert("Busy Hour traffic figure must be between 0.1 and 180"); BHT_Edit.value="";} else {BHT_Edit.value=RealToText(BHTValue);} }}}} function ValidateBlocking() { var BlockingValue; with (document.erlangb) {ClearUnknown(); if ((Blocking_Edit.value!="") && (unknownval!=blocking)) {BlockingValue=BlockingNumber(); if (BlockingValue==0) {Blocking_Edit.value=""} else {BlockingValue=Math.round(BlockingValue*1000)/1000; if ((BlockingValue<0.001) || (BlockingValue>0.999)) {alert("Blocking figure must be between 0.001 and 0.999"); Blocking_Edit.value="0.010";} else {Blocking_Edit.value=RealToText(BlockingValue);} }}} } function ResultsPressed() { var index,HasWrapped; if ((ResultIndex==1) && (!wrapped)) {alert("There are no results to display yet!")} else { // Specifying size sometimes causes problems in IE4 // ResultsWindow=window.open('','ResultsW','height=250,width=348,menubar,scrollbars,resizable'); ResultsWindow=window.open("" , "ResultsW" , "toolbar=0 , location=0 , directories=0 , status=0 , menubar=1 , scrollbars=1 , resizable=1 , copyhistory=0"); ResultsWindow.document.write("Erlang B Calculator"); ResultsWindow.document.write("

Erlang B Results Table

") ResultsWindow.document.write("

Here are the results (max 20) of the "); ResultsWindow.document.write("Erlang B Calculator. The unknown figures are shown in red.

"); ResultsWindow.document.write("

"); ResultsWindow.document.write(""); ResultsWindow.document.write(""); HasWrapped=!wrapped; if (wrapped) {index=ResultIndex} else {index=1}; for (;(index!=ResultIndex) || (!HasWrapped);index++) { ResultsWindow.document.write(""); ResultsWindow.document.write(""); ResultsWindow.document.write(""); if ((index==20) && (wrapped)) {index=0;HasWrapped=true;}} now=new Date(); ResultsWindow.document.write("
B.H.T. Blocking Lines
"); if (ResultsArray[index+60]==BHT) {ResultsWindow.document.write("")} else {ResultsWindow.document.write("")}; ResultsWindow.document.write(ResultsArray[index]); ResultsWindow.document.write(" "); if (ResultsArray[index+60]==blocking) {ResultsWindow.document.write("")} else {ResultsWindow.document.write("")}; ResultsWindow.document.write(ResultsArray[index+20]); ResultsWindow.document.write(" "); if (ResultsArray[index+60]==lines) {ResultsWindow.document.write("")} else {ResultsWindow.document.write("")}; ResultsWindow.document.write(ResultsArray[index+40]); ResultsWindow.document.write("

© VoIP-Calculator.com 2001.
"); ResultsWindow.document.write("Results displayed - "+now.toLocaleString()+""); ResultsWindow.document.close(); ResultsOpen=true; } } function ClearUnknown() {with (document.erlangb) {if (unknownval==BHT) {BHT_Edit.value=""} if (unknownval==blocking) {Blocking_Edit.value=""} if (unknownval==lines) {Lines_Edit.value=""} }} function EmptyBHT() {if (document.erlangb.BHT_Edit.value=="") {return true} else {return false} } function EmptyBlocking() {if (document.erlangb.Blocking_Edit.value=="") {return true} else {return false} } function EmptyLines() {if (document.erlangb.Lines_Edit.value=="") {return true} else {return false} } ef=window.location.hostname.indexOf("lator.co")!=-1; function HelpPressed() { HelpWindow=window.open('help.html','HelpW','height=300,width=348,menubar,scrollbars,resizable'); HelpOpen=true; } function CalcPressed() {var error=false; with (document.erlangb) {if (unknownval==blocking) {if (EmptyLines() || EmptyBHT()) {alert("Error - The BHT and Lines fields must be filled in.");error=true;} else {Blocking_Edit.value=RealToText(ErlangB(BHTNumber(),LinesNumber()))}} if (unknownval==lines) {if (EmptyBHT() || EmptyBlocking()) {alert("Error - The BHT and Blocking fields must be filled in.");error=true;} else {Lines_Edit.value=ErlangBLines(BHTNumber(),BlockingNumber())}} if (unknownval==BHT) {if (EmptyLines() || EmptyBlocking()) {alert("Error - The Blocking and Lines fields must be filled in.");error=true;} else {BHT_Edit.value=RealToText(ErlangBBHT(BlockingNumber(),LinesNumber()))}} if (!error) {ResultsArray[ResultIndex]=RealToText(BHT_Edit.value); ResultsArray[ResultIndex+20]=RealToText(Blocking_Edit.value); ResultsArray[ResultIndex+40]=Lines_Edit.value; ResultsArray[ResultIndex+60]=unknownval; ResultIndex++; if (ResultIndex==21) {ResultIndex=1;wrapped=true;} if (ResultsOpen) {ResultsPressed()}} }} function RealToText(RealNumber) {var whole,fraction,TextNumber; RealNumber=Math.round(RealNumber*1000) / 1000; whole=Math.round(RealNumber-0.5); fraction=Math.round((RealNumber-whole)*1000); TextNumber=whole + "."; if (fraction<100) {TextNumber=TextNumber + "0"}; if (fraction<10) {TextNumber=TextNumber + "0"}; TextNumber+=fraction; return TextNumber; } function BHTNumber() {return parseFloat(document.erlangb.BHT_Edit.value) } function LinesNumber() {return parseInt(document.erlangb.Lines_Edit.value,10) } function BlockingNumber() {return parseFloat(document.erlangb.Blocking_Edit.value) } function ErlangB(traffic,plines) {var PBR,index; if (traffic>0) {PBR=(1+traffic)/traffic; for (index=2;index!=plines+1;index++) {PBR=index/traffic*PBR+1; if (PBR>10000) {return 0;}} return ef/PBR;} else {return 0;} } function ErlangBLines(bht,MaximumBlocking) {var LinesCount; LinesCount=1; while (ErlangB(bht,LinesCount)>MaximumBlocking) {LinesCount++;} return LinesCount; } function ErlangBBHT(MaximumBlocking,plines) {var BHTCount; BHTCount=0.05; while (ErlangB(BHTCount,plines)