Event Handling and Web Forms Essay Example | Topics and Well Written Essays - 750 words

Event Handling and Web Forms - Essay Example An event takes place whenever the user performs an action. The user’s causes an event and when the web page reacts to this event true interactivity between the web page and the user is born. The start of event handling took place when Netscape version 2 browsers were launched; this browser supported JavaScript and hence also supported events. Netscape 2 supported only a few events. Mouse over and Mouse out were two events which became famous with this browser. The Netscape 2 browser was also able to detect the submission of a form, the resetting of form and the time when the page has completed loading (Jackson, 2007). However the problem started with the advent of browser wars between Netscape and IE. Both of them created completed incompatible event models. Thus at present we have to deal with three event models – the Netscape navigator 4(NN4), Internet explorer 4 and the most recent one – W3C model. The first step to ensure cross browser compatibility is to reg ister the event handler. There are four main ways of registering the event handler – inline, traditional, W3C and Microsoft. The best method is to use the traditional method as it is completely compatible across all the browsers and will not cause any problem in any of them. After registering the event; the actual script writing takes place. ... The area where the browser computability is the least is reading out the properties of the event. In this we have to ensure that very detailed object detection is used. The first step should be check if the property exists in the browser and if it does only then should the value be read out (D Flanagan, 2011) The last thing to be decided is the event order. The code –writer has to see if he wants the event to bubble up and if that is not the desired result; the propagation of the event should be stopped. The compatibility between different models is a problem; however if we take in to account the precautions mentioned above a workaround can be easily found for all the platforms. DQ 2 Web Forms Since their inception in the early 1990’s, Web forms have become the essential interface of the transactional Web. They are a central component of e-commerce applications and are use to collect business critical information. It has also been said that Web forms are changing the pa radigm of Business workflows. Do you agree with this? Discuss this in relation of Business workflows and data collection at various points of these workflows. Any company that is engaged in e-commerce has to deal with information at three stages – ordering of a product, processing of that order and shipping the product to the customer. Different information needs to be available at these three points and also needs to be transferred from one point to another. Web forms are one of the most exciting innovations of modern times. They allow the business to interact directly with clients, prospective customers and even the employees of the organisation. With the advent of web forms business workflows of

Reactivity of M-C bonds and catalytiv formation of heterocycles Essay

Reactivity of M-C bonds and catalytiv formation of heterocycles - Essay Example The second key element is the CH activation process and this process usually helps in electrophilic metal and acetate activation. The activation is achieved through combination of deprotonation as well as acetate which is an intramolecular base. Currently, close to 95% of all phenyl group activation relies on CH activation (Anastas & Warner, 1998). Current studies have showed the ease of activation of different types of CH bonds and some of these bonds are NH or NR types. This type of bond falls in type 1 of the heterocycles ligands and the second type is the vinyl group. This group is characterized by the formation of rings such as M ring which at times is an equivalent of p-cymene. The vinyl group which is type 2 of the heterocycles in ligands is able to react with alkynes after the process of CH activation. The ease of insertion of the various M-C bonds which comprises of the heterocycle, phenyl, and vinyl with alkynes are not yet known. This is because very limited research has b een done on this area. The activation of these M-C bonds with the alkynes is expected to give type 3 of the heterocycles in ligands (Chen et al., 2009). Some of the end products of catalysis with heterocycles produce effects during the activation process and update such kind of effects have never been researched. Therefore, the effects that they are capable of producing are not well known. Basically, this project will tend to unveil the synthesis of complexes in group 2 like D, 1,2-Diphenylethane-1,2-diol (II) and their various reactions with the alkynes to form either group 3 or group 4 heterocycles ligands (Sanford & Lyons, 2010). The obtained experimental results will therefore, be compared to the various results that are obtained through computational chemistry. These computational chemistry results will be the ones that were obtained by the various collaborators who were present at the University of Heriott Watt. PREPARATION OF FUNCTIONALIZED HETEROCYCLES STARTING MATERIALS AND PRODUCTS The starting materials are 1-chloro-isoquinoline together with benzotriazole. The two are combined through nucleophilic substitution method. The combination of these two gives ligand 1. The use of deprotonation can also be used in the preparation of these functionalized heterocycles such as NH or NR. The deprotonation is carried out on imidazolium chloride salt together with a strong base as the solvent. The reaction time is at an interval of 10 to 15 minutes before the next step is undertaken. Reaction pass this time at times yield wrong results and therefore, keen observations of this reaction time is recommended for purposes of accurate results. The preferred chemical apparatus is Schlenk flask together with stir bar. Stir bar is used to prevent heat loss during the homogeneous mixing of the reactants. After the formation of ligand 1 the cyclometallated complexes 2 which is ligand 2 is formed from the reaction of 2-vinylpyridine and trithiazyl trichloride (Ng, Zhou & Yu , 2012). The ligand 3 is also formed from the reaction of rubeanic acid and double cyclocondesation of oxalamidoxime. These kinds of ligands are useful during the formation of multinuclear and mononuclear metal complexes. The other products formed are Diisopropoxytitanium (III) Tetrahydroborate, 1(2 mmol) and lithium bis (2,4,6-triisopropylphenyl)hydroboratylmethylpolystyrene (9) A reaction between tetrahydroborate 1 of heterocycles 1 equivalent took place with a-hydroxyketones also of 1 equivalent for a time ranging between 5 to 15 minutes. The