Previewing HTML in a Web Browser

Microsoft Office 2000 uses the following technologies when saving documents as Web pages.

Some Web browsers do not support the complete set of these technologies, and some formatting and functions might not be displayed properly. For example, the following table shows the technologies supported in versions of Microsoft Internet Explorer.

Conditional comments

Conditional comments are used to control the display of elements in order to create a more consistent viewing experience. In order to make a number of features visible in a Web browser, Office specifies HTML elements that are used only by Web browsers to display content. Conditional comments are specified around these elements.

A conditional comment can have one of two forms. The downlevel-revealed form reveals the contents of the comment in Web browsers. The downlevel-hidden form hides the contents of the comment.

Like an ordinary HTML comment, a conditional comment is not recognized when used inside literal HTML text, such as in text within a Script element.

Conditional comments can be nested. The results are undefined if <![if]> and <![endif]> statements are not matched, or if the syntax of the expression in an <![if]> statement is ill-formed. Note that Internet Explorer 5 closes unmatched <![if]> statements at the end of a file, and any unmatched <![endif]> statements and <![if]> statements with ill-formed expressions are displayed as text.

Expressions follow normal precedence rules: parentheses and prefix operators are evaluated first, followed by & operators and | operators.

Version numbers

A version number consists of releases separated by dots, with the most significant release appearing first.

5.010beta.3032 specifies the releases 5, 01beta, and 3032.
5.999.a specifies the releases 5, 999, and a.

Compared from left to right, since 5 equals 5 and 010beta is less than 999, 5.010beta.3032 comes before 5.999.a.

An exact version number (such as the actual version number of a product) is assumed to have infinite precision in the sense that a specified version string of 5.2b is interpreted to mean 5.2b.0.0.0.0.0.0…

Each release string consists of letters and digits; these are separated into runs of just letters and runs of just digits. Again, the most significant part is on the left.

10alpha2 specifies the releases 10, alpha, and 2.
010beta specifies the releases 010 and beta.

Compared from left to right, since 10 equals 010 numerically and alpha is less than beta, 01alpha2 comes before 010beta.

Individual parts of a release are compared as follows:

1. Words precede numbers.
2. Words are ordered in case-insensitive alphabetical order.
3. Numbers are ordered in integer decimal order.

The following example shows the order of several releases.

4.a < 4.a0 < 4.aa < 4 = 4.0 < 4.0a < 4.1 < 4.5 < 4.510

The version number inside an expression refers to the entire set of versions represented by the specified release. For example, the expression <![if IE 5.2m ]> matches all versions of Internet Explorer in the release 5.2m, including 5.2m.beta1, 5.2m.0, and 5.2m.6.r3, but not 5.2 or 5. An expression can be made more exact by specifying more parts on the version number.

When inequalities are evaluated, the comparison is only done to the specified precision. So, for example, both <![if gt IE 5.2m ]> and <![if lt IE 5.2m ]> are false if the actual version number is 5.2m.6.r3, but both <![if gte IE 5.2m ]> and <![if lte IE 5.2m ]> are true.

Behavior

Uplevel-begin and uplevel-end comments

When the Web browser encounters an uplevel-begin comment, it evaluates the expression. If the expression is true, the content between the uplevel-begin and uplevel-end comments is displayed. If the expression is false, the content between the uplevel-begin and uplevel-end comments is ignored.

Downlevel-begin and downlevel-end comments

When the Web browser encounters a downlevel-begin comment, it evaluates the expression. If the expression is true, the content between the downlevel-begin and downlevel-end comments is displayed. If the expression is false, the content between the downlevel-begin and downlevel-end comments is ignored.

Expressions

Logical operators behave as follows:

Comparison operators behave as follows:

Examples

In the following example, the content is displayed if the browser is a version of Internet Explorer 5 or later.

<!-- [if IE]>
Here is some content
<![endif]--> 

This example displays the content in Internet Explorer 5, but not in later versions.

 
<!-- [if IE 5]>
Here is some content
<![endif]--> 

The next example displays the content in browsers other than Internet Explorer.

 
<!-- [if !IE]>
Here is some content
<![endif]--> 

This example displays the content if any version of the VG component is installed.

 
<!-- [if VG]>
Here is some content
<![endif]--> 

The following example displays the content if version 6 of the VG component is not installed.

 
<!-- [if !VG 6]>
Here is some content
<![endif]--> 

The next example displays the content if the VG component is installed and its version number is greater than 6.

 
<!-- [if gt VG 6]>
Here is some content
<![endif]--> 

This example displays the content if version 6 of the VG component is installed on the Macintosh.

 
<!-- [if MAC & VG 6]>
Here is some content
<![endif]--> 

The next example displays the content in Internet Explorer if the VG component is installed and its version number is less than 8.

 
<!-- [if IE & lt VG 8]>
Here is some content
<![endif]--> 

If values

The following table shows the If values used by Microsoft Office programs.