Preventing certain characters

Collapse
This topic is closed.
X
X
 
  • Time
  • Show
Clear All
new posts
  • Phil Amey

    Preventing certain characters

    I would like to prevent certain characters from being input to some form cells, e.g. ~ # ' and so on.

    I'm currently using this format to check the input data of cells -

    if (document.form1 .EMAIL.value == ""){
    alert("Please complete the E-Mail: field")
    document.form1. EMAIL.focus()
    validFlag = false
    return validFlag
    }

    It would also be nice to learn how to check this particular cell for a valid email address, I assume that you search for the @.

    Could someone show me how I could modify this to prevent characters of my choice.

    Kindest Regards - Philip Amey

  • Brian Genisio

    #2
    Re: Preventing certain characters

    Phil Amey wrote:
    [color=blue]
    > I would like to prevent certain characters from being input to some form cells, e.g. ~ # ' and so on.
    >
    > I'm currently using this format to check the input data of cells -
    >
    > if (document.form1 .EMAIL.value == ""){
    > alert("Please complete the E-Mail: field")
    > document.form1. EMAIL.focus()
    > validFlag = false
    > return validFlag
    > }
    >
    > It would also be nice to learn how to check this particular cell for a valid email address, I assume that you search for the @.
    >
    > Could someone show me how I could modify this to prevent characters of my choice.
    >
    > Kindest Regards - Philip Amey
    >[/color]

    For removing special characters, use the javascript string methods
    (indexOf, substr, split, join, etc) to do it the way you need.

    For email addresses, I like to make sure there is an @ character, and in
    the host side, there is a high-level domain *.* (*.com, *.net, *.edu,
    etc, but stay with *.*, since it it is tough to know which high-level
    domain names will exist in the future)

    VERY IMPORTANT: Do not rely on javascript to make sure your server-side
    form handler gets the correct input. If my browser does not support
    javascript, or I simply send the HTTP request by hand, I can _easily_
    circumvent the special characters, and break your form handler, if it
    does not handle the special characters as well.

    VERY IMPORTANT: Do not disregard the previous statement :)

    Good luck,
    Brian

    Comment

    Working...