How can I change all occurences of one character/word/substring to another in a string ???

Learn the power of regular expressions !

<script language="JavaScript"><!-- function write_Str() { document.getElementById("text1").value="... 200 / 201/ 202 / 203 / 204 / 205 / 206 / 207 / 208 / 209 /..."; } function change_Str() { var myStr =document.getElementById("text1").value; var myReg_1 = new RegExp( '20', "gi") ; myStr= myStr.replace( myReg_1 , '21' ) ; alert(myStr); } -->/script>