<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> </head> <body>of the typethe INPUT< City:= "text" ID = "City" name = "City" > < br > Air Quality: < P ID = "AQI" > </ P > < Script > var ARRY = [[ " Beijing " , 100 ], [ " Shanghai " , 90 ], [ " Dalian " , 50 ], [ " Shenyang " , 90 ]]; var ocity = Document.getElementById("city"); var oaqi = document.getElementById("aqi"); ocity.onblur = function(){ for(i=0;i<arry.length;i++){ if(arry[i][0] == ocity.value){ oaqi.innerHTML= arry[i][1]; break; }else{oaqi.innerHTML = "Please enter a city name! " ;} } } </ Script > </ body > </ HTML >