selecting text in a <input> tag in a grid cell

i can't select the text in a standard html <input> tag embedded in a awGrid cell, moving the mouse over the text or selecting the text with the shortcut SHIFT + pos1/end. Why ?

Also it was not possible to use the POS1 or END key before inserting the following lines into the html code:

awGrid.onKeyRight = function(event) { return true; }
awGrid.onKeyLeft = function(event) { return true; }
awGrid.onKeyShiftRight = function(event) { return true; }
awGrid.onKeyShiftLeft = function(event) { return true; }

Where is my mistake ? Does anybody has got an idea ???

Merry Christmas
Christian