select text range

select text.js

function createSelection(start, end, field) {

    if ( field.createTextRange ) {

        /* 
        IE calculates the end of selection range based 
        from the starting point.
        Other browsers will calculate end of selection from
        the beginning of given text node.
        */

        var newend = end - start;
        var selRange = field.createTextRange();
        selRange.collapse(true);
        selRange.moveStart("character", start);
        selRange.moveEnd("character", newend);
        selRange.select();
    } 

    /* For the other browsers */

    else if( field.setSelectionRange ){

        field.setSelectionRange(start, end);
    } 

    field.focus();
}

/* 
Usage 
*/

var target = document.getElementById("target-input-or-textarea");
createSelection(10, 20, target);