js设置光标位置

function getCaret(textbox)

{

var control = document.activeElement;

textbox.focus();

var rang = document.selection.createRange();

rang.setEndPoint("StartToStart",textbox.createTextRange())

control.focus();

return rang.text.length;

}

function setCaret(textbox,pos)

{

try

{

var r =textbox.createTextRange();

r.moveStart('character',pos);

r.collapse(true);

r.select();

}

catch(e)

{}

}

function selectLength(textbox,start,len)

{

try

{

var r =textbox.createTextRange();



r.moveEnd('character',len-(textbox.value.length-start));

r.moveStart('character',start);



r.select();

}

catch(e)

{//alert(e.description)}

}

function insertAtCaret(textbox,text)

{

textbox.focus();

document.selection.createRange().text = text;

}