To add to gellyfish's comment if you had strict and warnings on you would have been alerted to a stray 'i' (see the comment below). There were other quoting issues too (also commented). I've taken the liberty of adding some white space. I don't know if it will now do what you want but at least it compiles which imo is a good start. :-)

#!/bin/perl5

use strict;
use warnings;

my $JSCRIPT=<<END;   # added my
var cal = new CalendarPopup("testdiv");
cal.setCssPrefix("TEST");
cal.showYearNavigation();
END

my $JSCRIPT2=<<END2; # added my
writeSource("jscal1");
END2

print start_html(

  -style=>{
    -src=>[
      '/styles/print.css','/styles/yreg_lite_v5.css'
    ],
    -media => 'all'
   },
   
   -title=>'MIS - People Data', 
   
   -script=>[
      {
        -language => 'JavaScript',
        #-src =>  i  '/javascript/ValidateForm.js'
        -src => '/javascript/ValidateForm.js' # removed the i
      },
      {
        -language => 'JavaScript',
        -src => '/javascript/CalendarPopup.js'
      },
      {
        -language => 'JavaScript',
        -src => '/javascript/AnchorPosition.js'
      }, 
      {
        -language => 'JavaScript',
        -src => '/javascript/date.js'
      },
      {
        -language => 'JavaScript',
        -src => '/javascript/PopupWindow.js'
      },
      { 
        -id=>'jscal1',
        -code=>$JSCRIPT
      },
      $JSCRIPT2
  ]
);




print table(
  {
    -width=>'97%',
    -cellpadding=>4,
    -cellspacing=>5
  },
  Tr(
    {
      -align=>'RIGHT',  # quotes added
      -valign=>'TOP'    # quotes added
    },
    td( 
      submit(
        -name=>'Update',
        -value=>'Update',
        -onClick('ValidateForm(this.form)') # quotes added
      )
    )
  )
);
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