insert PCDATA from the child element into an attribute

I want to insert PCDATA from the child element into a selected node attribute

XML

<root>
  <tag>
     <tag1>SOME TEXT</tag1>
  </tag>
</root>

MY XSL

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xi="http://www.w3.org/2001/XInclude" version="1.0">

    <xsl:template match="root">
        <tag-out>
            <xsl:attribute name="text">
                <!-- What should I select? -->
                <xsl:value-of select="tag/tag1/???"/>
            </xsl:attribute>
        <tag-out>
    </xsl:template>

    ...........

</xsl:stylesheet>

Desired output XML

<root-out text="SOME TEXT"&开发者_如何学Cgt;
   <tag-out/>
</root-out>

Thanks

What's wrong with simply doing

   <tag-out text="{tag/tag1}"></tag-out>

? Of course your sample with

    <tag-out>
        <xsl:attribute name="text">

            <xsl:value-of select="tag/tag1"/>
        </xsl:attribute>
    <tag-out>

is also possible. But as your post is tagged XSLT 2.0 I would at least do

    <tag-out>
        <xsl:attribute name="text" select="tag/tag1"/>
    <tag-out>

if you really need xsl:attribute.