diff --git a/Spreadsheet/Excel/Writer/Parser.php b/Spreadsheet/Excel/Writer/Parser.php
index 3254cf8..ea4319a 100644
--- a/Spreadsheet/Excel/Writer/Parser.php
+++ b/Spreadsheet/Excel/Writer/Parser.php
@@ -1213,7 +1213,7 @@ class Spreadsheet_Excel_Writer_Parser extends PEAR
             default:
                 // if it's a reference
                 if (preg_match('/^\$?[A-Ia-i]?[A-Za-z]\$?[0-9]+$/',$token) and
-                   !ereg("[0-9]",$this->_lookahead) and 
+                   !preg_match("/[0-9]/",$this->_lookahead) and 
                    ($this->_lookahead != ':') and ($this->_lookahead != '.') and
                    ($this->_lookahead != '!'))
                 {
@@ -1221,39 +1221,39 @@ class Spreadsheet_Excel_Writer_Parser extends PEAR
                 }
                 // If it's an external reference (Sheet1!A1 or Sheet1:Sheet2!A1)
                 elseif (preg_match("/^\w+(\:\w+)?\![A-Ia-i]?[A-Za-z][0-9]+$/u",$token) and
-                       !ereg("[0-9]",$this->_lookahead) and
+                       !preg_match("/[0-9]/",$this->_lookahead) and
                        ($this->_lookahead != ':') and ($this->_lookahead != '.'))
                 {
                     return $token;
                 }
                 // If it's an external reference ('Sheet1'!A1 or 'Sheet1:Sheet2'!A1)
                 elseif (preg_match("/^'[\w -]+(\:[\w -]+)?'\![A-Ia-i]?[A-Za-z][0-9]+$/u",$token) and
-                       !ereg("[0-9]",$this->_lookahead) and
+                       !preg_match("/[0-9]/",$this->_lookahead) and
                        ($this->_lookahead != ':') and ($this->_lookahead != '.'))
                 {
                     return $token;
                 }
                 // if it's a range (A1:A2)
                 elseif (preg_match("/^(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+:(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+$/",$token) and 
-                       !ereg("[0-9]",$this->_lookahead))
+                       !preg_match("/[0-9]/",$this->_lookahead))
                 {
                     return $token;
                 }
                 // if it's a range (A1..A2)
                 elseif (preg_match("/^(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+\.\.(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+$/",$token) and 
-                       !ereg("[0-9]",$this->_lookahead))
+                       !preg_match("/[0-9]/",$this->_lookahead))
                 {
                     return $token;
                 }
                 // If it's an external range like Sheet1!A1 or Sheet1:Sheet2!A1:B2
                 elseif (preg_match("/^\w+(\:\w+)?\!([A-Ia-i]?[A-Za-z])?[0-9]+:([A-Ia-i]?[A-Za-z])?[0-9]+$/u",$token) and
-                       !ereg("[0-9]",$this->_lookahead))
+                       !preg_match("/[0-9]/",$this->_lookahead))
                 {
                     return $token;
                 }
                 // If it's an external range like 'Sheet1'!A1 or 'Sheet1:Sheet2'!A1:B2
                 elseif (preg_match("/^'[\w -]+(\:[\w -]+)?'\!([A-Ia-i]?[A-Za-z])?[0-9]+:([A-Ia-i]?[A-Za-z])?[0-9]+$/u",$token) and
-                       !ereg("[0-9]",$this->_lookahead))
+                       !preg_match("/[0-9]/",$this->_lookahead))
                 {
                     return $token;
                 }
@@ -1265,12 +1265,12 @@ class Spreadsheet_Excel_Writer_Parser extends PEAR
                     return $token;
                 }
                 // If it's a string (of maximum 255 characters)
-                elseif (ereg("^\"[^\"]{0,255}\"$",$token))
+                elseif (preg_match("/^\"[^\"]{0,255}\"$/",$token))
                 {
                     return $token;
                 }
                 // if it's a function call
-                elseif (eregi("^[A-Z0-9\xc0-\xdc\.]+$",$token) and ($this->_lookahead == "("))
+                elseif (preg_match("/^[A-Z0-9\xc0-\xdc\.]+$/i",$token) and ($this->_lookahead == "("))
                 {
                     return $token;
                 }
@@ -1377,7 +1377,7 @@ class Spreadsheet_Excel_Writer_Parser extends PEAR
     function _expression()
     {
         // If it's a string return a string node
-        if (ereg("^\"[^\"]{0,255}\"$", $this->_current_token)) {
+        if (preg_match("/^\"[^\"]{0,255}\"$/", $this->_current_token)) {
             $result = $this->_createTree($this->_current_token, '', '');
             $this->_advance();
             return $result;
@@ -1535,7 +1535,7 @@ class Spreadsheet_Excel_Writer_Parser extends PEAR
             return $result;
         }
         // if it's a function call
-        elseif (eregi("^[A-Z0-9\xc0-\xdc\.]+$",$this->_current_token))
+        elseif (preg_match("/^[A-Z0-9\xc0-\xdc\.]+$/i",$this->_current_token))
         {
             $result = $this->_func();
             return $result;