input输入框光标控制

//控制input输入框的光标
function set_text_value_position(tobj, spos) {
    // var tobj = document.getElementById(obj);
    if (spos < 0)
        spos = tobj.value.length;
    if (tobj.setSelectionRange) { //兼容火狐,谷歌
        setTimeout(function() {
            if (tobj.value == "0.0000") {
                tobj.setSelectionRange(spos, spos + 1);
            } else {
                tobj.setSelectionRange(spos, spos);
            }
            tobj.focus();
        }, 0);
    } else if (tobj.createTextRange) { //兼容IE
        var rng = tobj.createTextRange();
        rng.move('character', spos);
        rng.select();
    }
}