I need to copy all info from my xml file (actually i need to add new info into my xml file).
I use standart template :
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()" />
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
and I write test xml file :
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE products SYSTEM "products.dtd" >
<?xml-stylesheet type="text/xsl" href="../xsl/copy.xsl"?>
<products>
<category name="Audio And Video">
<subcategory name="Audio">
<good>
<producer>Dell</producer>
<model>QQ678</model>
<color>White</color>
<date_of_issue>12-12-2012</date_of_issue>
<not_in_stock>true</not_in_stock>
</good>
</subcategory>
<subcategory name="Video">
<good>
<producer>Samsung</producer>
<model>VH500</model>
<color>Black</color>
<date_of_issue>12-12-2006</date_of_issue>
<price>200</price>
</good>
<good>
<producer>Toshiba</producer>
<model>GP436</model>
<color>White</color>
<date_of_issue>12-12-2004</date_of_issue>
<not_in_stock>true</not_in_stock>
</good>
</subcategory>
</category>
<category name="Computers">
<subcategory name="Pocket">
<good>
<producer>HP</producer>
<model>rx371</model>
<color>Black</color>
<date_of_issue>31-01-2006</date_of_issue>
<not_in_stock>true</not_in_stock>
</good>
</subcategory>
</category>
</products>
And when i open this xml file in browser I think I will see the same xml file but it displays me: 
so where I made mistake. Please help me please to solve my problem
Your style sheet does nothing except copy the input to the output. As far as can be told from the browser output, it is doing that correctly. There is no problem in evidence here. Try outputting some HTML instead of just copying.