【正文】 to the big picture of Web development, you need to understand the concept of a serverside scripting language. If you39。ve programmed Web pages in Perl, PHP, JSP, or Cold Fusion before, you can safely skip this section – all of those are serverside scripting languages, and ASP works in much the same way. If you39。re ing to ASP armed only with knowledge of HTML (and perhaps with some CSS and/or JavaScript experience) then you39。ll find that serverside scripting is quite a bit different.Let me begin by giving you a quick review of how standard, nonASP Web pages work. As shown in Figure 1, the Web browser on the client puter (the puter belonging to the user) makes a request for a page, say (1). Assuming the requested file exists on the Web host puter where the Web Server software can find it, that software replies to the request by sending the file back to the browser (2). Any additional files (images, for example) required to display the page are requested and received in the same way. The protocol used for this exchange, and indeed for all munication between Web browsers and Web servers is called Hypertext Transfer Protocol (HTTP).If you39。ve ever used any JavaScript in your pages, you know that the requested Web page () can contain, in addition to plain HTML code, small programs written in JavaScript. These programs, or scripts, are read and executed by the Web browser while the page is displayed in the browser. So the Web browser must understand not only how to read HTML and display text.and images, but it must also be able to run JavaScript programs appearing inside Web pages. This arrangement, where the Web browser runs the script after receiving it from the Web server, is called clientside scripting. The name makes sense – all of the script runs on the clientside – the righthand side of Figure 1. The Web server is pletely oblivious to whether the file it is sending contains a script or not。 it’s all up to the browser (the client) to handle execution of the script.ASP fits into a different category of technologies, called serverside scripting, where it is no longer the browser running on the client that is responsible for running the script。 instead, it is the Web server that runs the script. This process is illustrated in Figure 2. As before, the Web browser requests a file (1). In this case, however, the filename ends with .asp (, for example), branding it as a file containing an ASP script that needs to be processed by the server. The server recognizes this, and instead of directly sending the requested file back to the browser, it sends the file to the ASP scripting engine (2). The engine is a ponent of the Web server software that can interpret ASP scripts and output the results as HTML. The trick here is that any given script can output different HTML each time it is run, so what es out of the ASP engine can be different for each client (browser) request. That dynamically generated page is then sent to the browser in response to its request (3), in exactly the same way as the static page was sent in the previous example.Just as when the page contained clientside JavaScript and the server was pletely unaware of this fact, when the page contains serverside ASP script, the browser does not know this at all. The ASP code contained in the page is interpreted and converted to plain HTML by the ASP engine before the browser gets to see it。 so as far as the browser is concerned an ASP page looks just like any normal Web page. All the work is done on the serverside。 thus the name, serverside scripting.附錄2：外文文獻(xiàn)中文譯文ASP簡(jiǎn)介ASP是構(gòu)建動(dòng)態(tài)網(wǎng)頁應(yīng)用的被實(shí)踐證明了的技術(shù)，為你需要?jiǎng)?chuàng)建任何的東西從一個(gè)基于圖片庫(kù)個(gè)人網(wǎng)頁到一個(gè)完整的目錄，為你的下一個(gè)商業(yè)項(xiàng)目提供全面的系統(tǒng)提供了強(qiáng)大的功能和靈活性。ASP唯一的特性即讓你選擇你最喜歡的腳本語言，像JavaScript 或者VBScript，然而VBScript是至今為止最流行的腳本語言。在本文中，我將帶你學(xué)習(xí)VBScript的基本syntax，包括變量，操作數(shù)和控制結(jié)構(gòu)。服務(wù)器端的腳本為了理解ASP適合Web開發(fā)的大圖片，你需要理解服務(wù)器端的腳本語言的概念。如果你用Perl, PHP, JSP 或者Cold Fusion編寫Web頁面前，你能夠安全略過這部分—所有這些是服務(wù)器端的腳本語言，ASP工作在許多相同的方式。如果你只是用HTML知識(shí)來輔助ASP(也許有過一些CSS或者Java腳本的經(jīng)歷),那么你將發(fā)現(xiàn)服務(wù)器端的腳本是有點(diǎn)不同之處的。 讓我開始給你一個(gè)標(biāo)準(zhǔn)的快速回顧，非ASP Web網(wǎng)頁工作。圖1中顯示客戶端的計(jì)算機(jī)（計(jì)算機(jī)屬于用戶）Web瀏覽器對(duì)頁面做請(qǐng)求即html (1)文件。假定在Web主機(jī)上存在被請(qǐng)求的文件，Web服務(wù)器軟件能發(fā)現(xiàn)它，軟件能通過發(fā)回文件給瀏覽器來回應(yīng)請(qǐng)求。任何附加文件（如圖象文件）要求顯示頁面是用同樣的方式請(qǐng)求和接收。協(xié)議用做交易，的確Web瀏覽器和Web服務(wù)器通信是叫做HTTP。如果你曾經(jīng)在你的網(wǎng)頁上用過Java腳本，你知道請(qǐng)求Web網(wǎng)頁（html文件）能包含除了普通HTML代碼，用Java腳本寫的小程序。這些程序或者腳本通過Web瀏覽器是可讀可執(zhí)行的當(dāng)頁面顯示在瀏覽器上時(shí)。所以Web瀏覽器必須理解怎么讀HTML和顯示文本和圖象，但是它必須能運(yùn)行顯示在Web頁面的Java腳本程序。瀏覽器收到Web服務(wù)器這個(gè)安排后運(yùn)行腳本，這個(gè)安排叫客戶端腳本。在圖1右手邊所有名字有意義的腳本在客護(hù)端運(yùn)行。Web服務(wù)器文件發(fā)送是否包含腳本是完全健忘的，這是瀏覽器（客戶端）處理執(zhí)行腳本。ASP適合不同的技術(shù)種類，叫客戶端腳本，它不在瀏覽器運(yùn)行客戶端而是在Web服務(wù)器上負(fù)責(zé)運(yùn)行腳本。這個(gè)過程在圖2中描繪。 像前面一樣，Web瀏覽器請(qǐng)求文件（1）然而在這樣的情況下，文件名末尾用asp（如文件asp），標(biāo)志著這個(gè)文件包含ASP腳本需要服務(wù)器來處理。服務(wù)器認(rèn)識(shí)這個(gè)，代替直接送請(qǐng)求文件給瀏覽器，它送文件給ASP腳本引擎（2）引擎是Web服務(wù)器的重要軟件，它能夠解釋ASP腳本和作為HTML輸出結(jié)果。這里的訣竅是任何已給的腳本每次運(yùn)行能輸出不同的HTML，所以ASP引擎的出現(xiàn)能對(duì)每一個(gè)客戶（瀏覽器）請(qǐng)求是不同的。那動(dòng)態(tài)生成的網(wǎng)頁被送到瀏覽器以響應(yīng)它的請(qǐng)求，這跟以前的靜態(tài)網(wǎng)頁有相同的方式。正象頁面包含客戶端的Java腳本和服務(wù)器是完全沒有意識(shí)到這個(gè)事實(shí)，當(dāng)頁面包含服務(wù)器端的ASP腳本，瀏覽器是根本不知道的。ASP代碼包含在頁面被解釋和傳送到ASP頁面看起來像其它任何普通的Web頁面。所有的工作在服務(wù)器端，所以名字就是服務(wù)器端腳本。