How to write javascript

/*This is code currently running on our servers. This snippet generates 3 lines of javascript. Everything is set to a variable. For example, JSASSIGN == " = ". This isn't an isolated case, either. There are literally thousands of lines of code just like this which generate critical HTML and javascript.*/


            // create add row js.
            StringBuffer addRowJS = new
                // declare var
                StringBuffer(JSVAR_DECLARE)
                .append(JSVARNAME1)
                .append(JSASSIGN)
                .append(domCreateElem(JS_TR))  // to be added to later
                .append(JSEND_STMT)

                // obtain new row index
                .append(JSVAR_DECLARE)
                .append(JSVARNAME2)
                .append(JSASSIGN)
                .append("parseInt(")
                .append(FORMNAME).append(INPUTNAME).append(".").append(JSVALUE)
                .append(")")
                .append(JSEND_STMT)

                // set ID of newRow
                .append(JSVARNAME1)
                .append(".id='")
                .append(this.prefix(id)).append(JSVARNAME2)
                .append("'+").append(JSVARNAME2)
                .append(JSEND_STMT)
                ;