What I want to achieve is as follows:
For example, there is a symbol which represents a table on a web page, a user can drag this element to any place on the web page, when the user looses the cursor, a dialogue box will pop up to ask the user to input values of attributes, for example,the number of columns, the number of rows, after the input, the corresponding table will come out at the place where the user chose. Of course, the symbol which represents a table is still at the original place. It is like a web version of dreamweaver. How to do this with Javascript?