Javaweb03-html Notes (iv)

1.1 Use JS to complete the registration page form prompt and check 1.1.1 requirements:

Registering the page before it is a popup dialog is not particularly friendly in the form of a check! You can display the error message after the text box. And when the cursor falls into the text box, the message prompts.
1.1.2 Analysis: 1.1.2.1 Technical Analysis:
"JS Output"

• document.getElementById (""). Innerhtml= "HTML code";
• document.write ("");
  "JS Event"
• Onfocus: Get focus.
• Onblur: Lose focus.

• OnSubmit: At the time of submission.
  1.1.2.2 Step Analysis:
  "Step One" creates an HTML document
  Step two adds an event to the text box you want to check.
  "Step three" trigger function
  Step four writes the contents of a hint to the area of the HTML after the text box in the function.
  1.1.3 Code implementation:

  function Tips (id,content) {document.getElementById (id+ "Span"). InnerHTML = "<font color= ' red '                    > "+content+" </font> "; } function Checkform () {//To determine that the user name cannot be empty: Var Usernam                            E = document.getElementById ("username"). Value; if (username = = "") {document.getElementById ("Usernamespan"). InnerHTML = "<font color = ' Red ' > username cannot be empty!                                    </font> ";                            return false;                            } var password = document.getElementById ("password"). Value; if (password = = "") {document.getElementById ("Passwordspan"). InnerHTML = "<font color = ' Red ' > Password cannot be empty!                                    </font> ";                            return false; }}1.1.4 Summary: Summary of the events of 1.1.4.1 JS:

• OnLoad:
• OnClick:
• OnSubmit:
• Onfocus:
• Onblur:
• OnChange: The drop-down list changes the event.
• OnDblClick: Double-click an element's event.
  Keyboard Manipulation Events:
• OnKeyDown:
• OnKeyUp:
• onkeypress
  Mouse Action Events:
• OnMouseMove
• onmouseout:
• onmouseover
• OnMouseDown
• OnMouseUp

Javaweb03-html Notes (iv)