Javascript function to enable a particular select box option or all the options in a select box

Javascript function to enable a particular select box option or all the options in a select box Function takes parameters as selboxId - Id of the select box selIndex - the index position of the option element to be enabled JS function to enable a particular select box option by passing its selected index. if no selected Index is passed to the function it enables all the options of select box. It check whether the selectbox ID is not null it checks whether the select Index is specified, if not it is set to -1 It checks whether the object is present in the form It loops through the options in select box if selected index is -1 then all options are enabled if select index is given that option alone is enabled Scroll down for the JS Code:
JS Code // function to enable a particular select box option by passing its selected index //if no selected Index is passed to the function it enables all the options of select box function enableOption(selboxId,selIndex){ //checks whether the select Index is specified, if not it is set to -1 if( !selIndex ) selIndex=-1; // check whether the selectbox ID is not null if( selboxId != "" ){ //checks whether the object is present in the form if( document.getElementById(selboxId) ){ //looping through the options in select box for( selInd=0; selInd < document.getElementById(selboxId).options.length ; selInd++ ){ //if selected index is -1 then all options are enabled if( selIndex < 0 ) document.getElementById(selboxId).options[selInd].disabled=false; else{ //if select index is given that option alone is enabled if( selInd == selIndex ) document.getElementById(selboxId).options[selInd].disabled=false; else document.getElementById(selboxId).options[selInd].disabled=true; } } } } }