【正文】 at W3C and elsewhere are making it possible to write standardbased DHTML that works for all pliant DHTML involves three aspects. —for crossbrowser scripting(Chapter9) Style Sheets(CSS)—for style and presentation control (Chapter6) Object Model(DOM)—for a uniform programming interface to access and manipulate the Web page as a document When these three aspects are bined,you get the ability to program changes in Web pages in reaction to useror browsergenerated ,you can make HTML pages more dynamic. Popular with Web developers,supported by all major browsers,and standardized,JavaScript provides the ability to program browser actions in response to have true crossplatform DHTML,we still need a uniform way for JavaScript to access and manipulate Web brings us to the DOM. What is DOM? The objective of unit and integration testing was to ensure that the code implemented the design properly。 當這三個方面都具備了，你就得到了改變網(wǎng)頁在用 戶或者瀏覽器生成響應事件的能力。 同樣種類的交流問題會出現(xiàn)在系統(tǒng)設計中。 例如，假設你正在測 試組件 A， B 和 C。因為測試的目標在于發(fā)現(xiàn)盡可能多的錯誤，這與錯誤存在于哪里有關。如果我們認為系統(tǒng)符合需要，然后我們將擁有一個通過驗證的系統(tǒng)；也就是說經(jīng)驗證我們的設計已經(jīng)達到了用戶需求。相似地，我們可以把系統(tǒng)分成一系列的子系統(tǒng)并在一個子系 統(tǒng)里執(zhí)行系統(tǒng)測試?？蛻粢矔y試系統(tǒng)，確保系統(tǒng)符合他們對需求的理解，而他們的理解可能與開發(fā)人員的理解不同。 系統(tǒng)測試流程 在系統(tǒng)測試中有以下幾個步驟： 這些步驟在插圖 中。當你把它們?nèi)齻€放在一起進行測試時，你發(fā)現(xiàn) A 通過一個參數(shù)到達 C 是不正確的。或者說我們清楚顧客的需求，但是可能措辭糟糕而導致在我們之后閱讀需求說明書的人發(fā)生曲解并進而使用了他們的錯誤理解。 隨著網(wǎng)絡開發(fā)的流行，被所有的專業(yè)瀏覽器和標準所支持， JavaScript 提供了編寫瀏覽器響應事件行為的能力。faults detected early are easier and cheaper to ,plete and early testing can helo not only to detect faults quickly,but also to isolate the causes more early. shows the reasons for faults,not evidence of testing aims to uncover as many faults as possible,it is concerned with where they may how faults are created gives us clues about where to look when testing a system. System Testing Process There are several steps in testing a system: testing testing testing testing The steps are illustrated in Figure step has a different focus,and a step’s success depends on its goal or ,it is helpful to review the purpose of each step of system testing. Process Objective. Initially,we test the functions performed by the begin with a set of ponents that were tested individually and then function test checks that the integrated system performs its functions as specified in the example,a function test of a bank account package verifies that the package can correctly credit a deposit,enter a withdrawal,calculate interest,print the balance,and so on. Once the test team is convinced that the functions work as specified,the performance test pares the integrated ponents with the nonfunctional system security,accuracy,speed,and reliability,constrain the way in which the system functions are instance,a performance test of the bank account package evaluates the speed with which calculations are made,the preci